Python Documentation contents¶
- What’s New in Python
- What’s New In Python 3.13
- Summary – Release Highlights
- New Features
- Other Language Changes
- New Modules
- Improved Modules
- argparse
- array
- ast
- asyncio
- base64
- compileall
- concurrent.futures
- configparser
- copy
- ctypes
- dbm
- dis
- doctest
- fractions
- glob
- importlib
- io
- ipaddress
- itertools
- marshal
- math
- mimetypes
- mmap
- multiprocessing
- os
- os.path
- pathlib
- pdb
- queue
- random
- re
- shutil
- site
- sqlite3
- ssl
- statistics
- subprocess
- sys
- tempfile
- time
- tkinter
- traceback
- types
- typing
- unicodedata
- venv
- warnings
- xml
- zipimport
- Optimizations
- Removed Modules And APIs
- New Deprecations
- CPython Bytecode Changes
- C API Changes
- Build Changes
- Porting to Python 3.13
- Regression Test Changes
- What’s New In Python 3.12
- What’s New In Python 3.11
- Summary – Release highlights
- New Features
- New Features Related to Type Hints
- Other Language Changes
- Other CPython Implementation Changes
- New Modules
- Improved Modules
- Optimizations
- Faster CPython
- CPython bytecode changes
- Deprecated
- Pending Removal in Python 3.12
- Removed
- Porting to Python 3.11
- Build Changes
- C API Changes
- Notable changes in 3.11.4
- Notable changes in 3.11.5
- What’s New In Python 3.10
- Summary – Release highlights
- New Features
- New Features Related to Type Hints
- Other Language Changes
- New Modules
- Improved Modules
- asyncio
- argparse
- array
- asynchat, asyncore, smtpd
- base64
- bdb
- bisect
- codecs
- collections.abc
- contextlib
- curses
- dataclasses
- distutils
- doctest
- encodings
- enum
- fileinput
- faulthandler
- gc
- glob
- hashlib
- hmac
- IDLE and idlelib
- importlib.metadata
- inspect
- itertools
- linecache
- os
- os.path
- pathlib
- platform
- pprint
- py_compile
- pyclbr
- shelve
- statistics
- site
- socket
- ssl
- sqlite3
- sys
- _thread
- threading
- traceback
- types
- typing
- unittest
- urllib.parse
- xml
- zipimport
- Optimizations
- Deprecated
- Removed
- Porting to Python 3.10
- CPython bytecode changes
- Build Changes
- C API Changes
- Notable security feature in 3.10.7
- Notable security feature in 3.10.8
- Notable changes in 3.10.12
- What’s New In Python 3.9
- Summary – Release highlights
- You should check for DeprecationWarning in your code
- New Features
- Other Language Changes
- New Modules
- Improved Modules
- Optimizations
- Deprecated
- Removed
- Porting to Python 3.9
- Build Changes
- C API Changes
- Notable changes in Python 3.9.1
- Notable changes in Python 3.9.2
- Notable changes in Python 3.9.3
- Notable changes in Python 3.9.5
- Notable security feature in 3.9.14
- Notable changes in 3.9.17
- What’s New In Python 3.8
- Summary – Release highlights
- New Features
- Assignment expressions
- Positional-only parameters
- Parallel filesystem cache for compiled bytecode files
- Debug build uses the same ABI as release build
- f-strings support
=
for self-documenting expressions and debugging - PEP 578: Python Runtime Audit Hooks
- PEP 587: Python Initialization Configuration
- PEP 590: Vectorcall: a fast calling protocol for CPython
- Pickle protocol 5 with out-of-band data buffers
- Other Language Changes
- New Modules
- Improved Modules
- ast
- asyncio
- builtins
- collections
- cProfile
- csv
- curses
- ctypes
- datetime
- functools
- gc
- gettext
- gzip
- IDLE and idlelib
- inspect
- io
- itertools
- json.tool
- logging
- math
- mmap
- multiprocessing
- os
- os.path
- pathlib
- pickle
- plistlib
- pprint
- py_compile
- shlex
- shutil
- socket
- ssl
- statistics
- sys
- tarfile
- threading
- tokenize
- tkinter
- time
- typing
- unicodedata
- unittest
- venv
- weakref
- xml
- xmlrpc
- Optimizations
- Build and C API Changes
- Deprecated
- API and Feature Removals
- Porting to Python 3.8
- Notable changes in Python 3.8.1
- Notable changes in Python 3.8.2
- Notable changes in Python 3.8.3
- Notable changes in Python 3.8.8
- Notable changes in Python 3.8.9
- Notable changes in Python 3.8.10
- Notable changes in Python 3.8.10
- Notable changes in Python 3.8.12
- Notable security feature in 3.8.14
- Notable changes in 3.8.17
- What’s New In Python 3.7
- Summary – Release Highlights
- New Features
- PEP 563: Postponed Evaluation of Annotations
- PEP 538: Legacy C Locale Coercion
- PEP 540: Forced UTF-8 Runtime Mode
- PEP 553: Built-in
breakpoint()
- PEP 539: New C API for Thread-Local Storage
- PEP 562: Customization of Access to Module Attributes
- PEP 564: New Time Functions With Nanosecond Resolution
- PEP 565: Show DeprecationWarning in
__main__
- PEP 560: Core Support for
typing
module and Generic Types - PEP 552: Hash-based .pyc Files
- PEP 545: Python Documentation Translations
- Python Development Mode (-X dev)
- Other Language Changes
- New Modules
- Improved Modules
- argparse
- asyncio
- binascii
- calendar
- collections
- compileall
- concurrent.futures
- contextlib
- cProfile
- crypt
- datetime
- dbm
- decimal
- dis
- distutils
- enum
- functools
- gc
- hmac
- http.client
- http.server
- idlelib and IDLE
- importlib
- io
- ipaddress
- itertools
- locale
- logging
- math
- mimetypes
- msilib
- multiprocessing
- os
- pathlib
- pdb
- py_compile
- pydoc
- queue
- re
- signal
- socket
- socketserver
- sqlite3
- ssl
- string
- subprocess
- sys
- time
- tkinter
- tracemalloc
- types
- unicodedata
- unittest
- unittest.mock
- urllib.parse
- uu
- uuid
- warnings
- xml
- xml.etree
- xmlrpc.server
- zipapp
- zipfile
- C API Changes
- Build Changes
- Optimizations
- Other CPython Implementation Changes
- Deprecated Python Behavior
- Deprecated Python modules, functions and methods
- Deprecated functions and types of the C API
- Platform Support Removals
- API and Feature Removals
- Module Removals
- Windows-only Changes
- Porting to Python 3.7
- Notable changes in Python 3.7.1
- Notable changes in Python 3.7.2
- Notable changes in Python 3.7.6
- Notable changes in Python 3.7.10
- Notable changes in Python 3.7.11
- Notable security feature in 3.7.14
- What’s New In Python 3.6
- Summary – Release highlights
- New Features
- PEP 498: Formatted string literals
- PEP 526: Syntax for variable annotations
- PEP 515: Underscores in Numeric Literals
- PEP 525: Asynchronous Generators
- PEP 530: Asynchronous Comprehensions
- PEP 487: Simpler customization of class creation
- PEP 487: Descriptor Protocol Enhancements
- PEP 519: Adding a file system path protocol
- PEP 495: Local Time Disambiguation
- PEP 529: Change Windows filesystem encoding to UTF-8
- PEP 528: Change Windows console encoding to UTF-8
- PEP 520: Preserving Class Attribute Definition Order
- PEP 468: Preserving Keyword Argument Order
- New dict implementation
- PEP 523: Adding a frame evaluation API to CPython
- PYTHONMALLOC environment variable
- DTrace and SystemTap probing support
- Other Language Changes
- New Modules
- Improved Modules
- array
- ast
- asyncio
- binascii
- cmath
- collections
- concurrent.futures
- contextlib
- datetime
- decimal
- distutils
- encodings
- enum
- faulthandler
- fileinput
- hashlib
- http.client
- idlelib and IDLE
- importlib
- inspect
- json
- logging
- math
- multiprocessing
- os
- pathlib
- pdb
- pickle
- pickletools
- pydoc
- random
- re
- readline
- rlcompleter
- shlex
- site
- sqlite3
- socket
- socketserver
- ssl
- statistics
- struct
- subprocess
- sys
- telnetlib
- time
- timeit
- tkinter
- traceback
- tracemalloc
- typing
- unicodedata
- unittest.mock
- urllib.request
- urllib.robotparser
- venv
- warnings
- winreg
- winsound
- xmlrpc.client
- zipfile
- zlib
- Optimizations
- Build and C API Changes
- Other Improvements
- Deprecated
- Removed
- Porting to Python 3.6
- Notable changes in Python 3.6.2
- Notable changes in Python 3.6.4
- Notable changes in Python 3.6.5
- Notable changes in Python 3.6.7
- Notable changes in Python 3.6.10
- Notable changes in Python 3.6.13
- Notable changes in Python 3.6.14
- What’s New In Python 3.5
- Summary – Release highlights
- New Features
- PEP 492 - Coroutines with async and await syntax
- PEP 465 - A dedicated infix operator for matrix multiplication
- PEP 448 - Additional Unpacking Generalizations
- PEP 461 - percent formatting support for bytes and bytearray
- PEP 484 - Type Hints
- PEP 471 - os.scandir() function – a better and faster directory iterator
- PEP 475: Retry system calls failing with EINTR
- PEP 479: Change StopIteration handling inside generators
- PEP 485: A function for testing approximate equality
- PEP 486: Make the Python Launcher aware of virtual environments
- PEP 488: Elimination of PYO files
- PEP 489: Multi-phase extension module initialization
- Other Language Changes
- New Modules
- Improved Modules
- argparse
- asyncio
- bz2
- cgi
- cmath
- code
- collections
- collections.abc
- compileall
- concurrent.futures
- configparser
- contextlib
- csv
- curses
- dbm
- difflib
- distutils
- doctest
- enum
- faulthandler
- functools
- glob
- gzip
- heapq
- http
- http.client
- idlelib and IDLE
- imaplib
- imghdr
- importlib
- inspect
- io
- ipaddress
- json
- linecache
- locale
- logging
- lzma
- math
- multiprocessing
- operator
- os
- pathlib
- pickle
- poplib
- re
- readline
- selectors
- shutil
- signal
- smtpd
- smtplib
- sndhdr
- socket
- ssl
- sqlite3
- subprocess
- sys
- sysconfig
- tarfile
- threading
- time
- timeit
- tkinter
- traceback
- types
- unicodedata
- unittest
- unittest.mock
- urllib
- wsgiref
- xmlrpc
- xml.sax
- zipfile
- Other module-level changes
- Optimizations
- Build and C API Changes
- Deprecated
- Removed
- Porting to Python 3.5
- Notable changes in Python 3.5.4
- What’s New In Python 3.4
- Summary – Release Highlights
- New Features
- New Modules
- Improved Modules
- abc
- aifc
- argparse
- audioop
- base64
- collections
- colorsys
- contextlib
- dbm
- dis
- doctest
- filecmp
- functools
- gc
- glob
- hashlib
- hmac
- html
- http
- idlelib and IDLE
- importlib
- inspect
- ipaddress
- logging
- marshal
- mmap
- multiprocessing
- operator
- os
- pdb
- pickle
- plistlib
- poplib
- pprint
- pty
- pydoc
- re
- resource
- select
- shelve
- shutil
- smtpd
- smtplib
- socket
- sqlite3
- ssl
- stat
- struct
- subprocess
- sunau
- sys
- tarfile
- textwrap
- threading
- traceback
- types
- urllib
- unittest
- venv
- wave
- weakref
- xml.etree
- zipfile
- CPython Implementation Changes
- Deprecated
- Removed
- Porting to Python 3.4
- Changed in 3.4.3
- What’s New In Python 3.3
- Summary – Release highlights
- PEP 405: Virtual Environments
- PEP 420: Implicit Namespace Packages
- PEP 3118: New memoryview implementation and buffer protocol documentation
- PEP 393: Flexible String Representation
- PEP 397: Python Launcher for Windows
- PEP 3151: Reworking the OS and IO exception hierarchy
- PEP 380: Syntax for Delegating to a Subgenerator
- PEP 409: Suppressing exception context
- PEP 414: Explicit Unicode literals
- PEP 3155: Qualified name for classes and functions
- PEP 412: Key-Sharing Dictionary
- PEP 362: Function Signature Object
- PEP 421: Adding sys.implementation
- Using importlib as the Implementation of Import
- Other Language Changes
- A Finer-Grained Import Lock
- Builtin functions and types
- New Modules
- Improved Modules
- abc
- array
- base64
- binascii
- bz2
- codecs
- collections
- contextlib
- crypt
- curses
- datetime
- decimal
- ftplib
- functools
- gc
- hmac
- http
- html
- imaplib
- inspect
- io
- itertools
- logging
- math
- mmap
- multiprocessing
- nntplib
- os
- pdb
- pickle
- pydoc
- re
- sched
- select
- shlex
- shutil
- signal
- smtpd
- smtplib
- socket
- socketserver
- sqlite3
- ssl
- stat
- struct
- subprocess
- sys
- tarfile
- tempfile
- textwrap
- threading
- time
- types
- unittest
- urllib
- webbrowser
- xml.etree.ElementTree
- zlib
- Optimizations
- Build and C API Changes
- Deprecated
- Porting to Python 3.3
- What’s New In Python 3.2
- PEP 384: Defining a Stable ABI
- PEP 389: Argparse Command Line Parsing Module
- PEP 391: Dictionary Based Configuration for Logging
- PEP 3148: The
concurrent.futures
module - PEP 3147: PYC Repository Directories
- PEP 3149: ABI Version Tagged .so Files
- PEP 3333: Python Web Server Gateway Interface v1.0.1
- Other Language Changes
- New, Improved, and Deprecated Modules
- elementtree
- functools
- itertools
- collections
- threading
- datetime and time
- math
- abc
- io
- reprlib
- logging
- csv
- contextlib
- decimal and fractions
- ftp
- popen
- select
- gzip and zipfile
- tarfile
- hashlib
- ast
- os
- shutil
- sqlite3
- html
- socket
- ssl
- nntp
- certificates
- imaplib
- http.client
- unittest
- random
- poplib
- asyncore
- tempfile
- inspect
- pydoc
- dis
- dbm
- ctypes
- site
- sysconfig
- pdb
- configparser
- urllib.parse
- mailbox
- turtledemo
- Multi-threading
- Optimizations
- Unicode
- Codecs
- Documentation
- IDLE
- Code Repository
- Build and C API Changes
- Porting to Python 3.2
- What’s New In Python 3.1
- What’s New In Python 3.0
- What’s New in Python 2.7
- The Future for Python 2.x
- Changes to the Handling of Deprecation Warnings
- Python 3.1 Features
- PEP 372: Adding an Ordered Dictionary to collections
- PEP 378: Format Specifier for Thousands Separator
- PEP 389: The argparse Module for Parsing Command Lines
- PEP 391: Dictionary-Based Configuration For Logging
- PEP 3106: Dictionary Views
- PEP 3137: The memoryview Object
- Other Language Changes
- New and Improved Modules
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.7
- New Features Added to Python 2.7 Maintenance Releases
- Two new environment variables for debug mode
- PEP 434: IDLE Enhancement Exception for All Branches
- PEP 466: Network Security Enhancements for Python 2.7
- PEP 477: Backport ensurepip (PEP 453) to Python 2.7
- PEP 476: Enabling certificate verification by default for stdlib http clients
- PEP 493: HTTPS verification migration tools for Python 2.7
- New
make regen-all
build target - Removal of
make touch
build target
- Acknowledgements
- What’s New in Python 2.6
- Python 3.0
- Changes to the Development Process
- PEP 343: The ‘with’ statement
- PEP 366: Explicit Relative Imports From a Main Module
- PEP 370: Per-user
site-packages
Directory - PEP 371: The
multiprocessing
Package - PEP 3101: Advanced String Formatting
- PEP 3105:
print
As a Function - PEP 3110: Exception-Handling Changes
- PEP 3112: Byte Literals
- PEP 3116: New I/O Library
- PEP 3118: Revised Buffer Protocol
- PEP 3119: Abstract Base Classes
- PEP 3127: Integer Literal Support and Syntax
- PEP 3129: Class Decorators
- PEP 3141: A Type Hierarchy for Numbers
- Other Language Changes
- New and Improved Modules
- Deprecations and Removals
- Build and C API Changes
- Porting to Python 2.6
- Acknowledgements
- What’s New in Python 2.5
- PEP 308: Conditional Expressions
- PEP 309: Partial Function Application
- PEP 314: Metadata for Python Software Packages v1.1
- PEP 328: Absolute and Relative Imports
- PEP 338: Executing Modules as Scripts
- PEP 341: Unified try/except/finally
- PEP 342: New Generator Features
- PEP 343: The ‘with’ statement
- PEP 352: Exceptions as New-Style Classes
- PEP 353: Using ssize_t as the index type
- PEP 357: The ‘__index__’ method
- Other Language Changes
- New, Improved, and Removed Modules
- Build and C API Changes
- Porting to Python 2.5
- Acknowledgements
- What’s New in Python 2.4
- PEP 218: Built-In Set Objects
- PEP 237: Unifying Long Integers and Integers
- PEP 289: Generator Expressions
- PEP 292: Simpler String Substitutions
- PEP 318: Decorators for Functions and Methods
- PEP 322: Reverse Iteration
- PEP 324: New subprocess Module
- PEP 327: Decimal Data Type
- PEP 328: Multi-line Imports
- PEP 331: Locale-Independent Float/String Conversions
- Other Language Changes
- New, Improved, and Deprecated Modules
- Build and C API Changes
- Porting to Python 2.4
- Acknowledgements
- What’s New in Python 2.3
- PEP 218: A Standard Set Datatype
- PEP 255: Simple Generators
- PEP 263: Source Code Encodings
- PEP 273: Importing Modules from ZIP Archives
- PEP 277: Unicode file name support for Windows NT
- PEP 278: Universal Newline Support
- PEP 279: enumerate()
- PEP 282: The logging Package
- PEP 285: A Boolean Type
- PEP 293: Codec Error Handling Callbacks
- PEP 301: Package Index and Metadata for Distutils
- PEP 302: New Import Hooks
- PEP 305: Comma-separated Files
- PEP 307: Pickle Enhancements
- Extended Slices
- Other Language Changes
- New, Improved, and Deprecated Modules
- Pymalloc: A Specialized Object Allocator
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.3
- Acknowledgements
- What’s New in Python 2.2
- Introduction
- PEPs 252 and 253: Type and Class Changes
- PEP 234: Iterators
- PEP 255: Simple Generators
- PEP 237: Unifying Long Integers and Integers
- PEP 238: Changing the Division Operator
- Unicode Changes
- PEP 227: Nested Scopes
- New and Improved Modules
- Interpreter Changes and Fixes
- Other Changes and Fixes
- Acknowledgements
- What’s New in Python 2.1
- Introduction
- PEP 227: Nested Scopes
- PEP 236: __future__ Directives
- PEP 207: Rich Comparisons
- PEP 230: Warning Framework
- PEP 229: New Build System
- PEP 205: Weak References
- PEP 232: Function Attributes
- PEP 235: Importing Modules on Case-Insensitive Platforms
- PEP 217: Interactive Display Hook
- PEP 208: New Coercion Model
- PEP 241: Metadata in Python Packages
- New and Improved Modules
- Other Changes and Fixes
- Acknowledgements
- What’s New in Python 2.0
- Introduction
- What About Python 1.6?
- New Development Process
- Unicode
- List Comprehensions
- Augmented Assignment
- String Methods
- Garbage Collection of Cycles
- Other Core Changes
- Porting to 2.0
- Extending/Embedding Changes
- Distutils: Making Modules Easy to Install
- XML Modules
- Module changes
- New modules
- IDLE Improvements
- Deleted and Deprecated Modules
- Acknowledgements
- Changelog
- Python next
- Python 3.13.0 final
- Python 3.13.0 release candidate 3
- Python 3.13.0 release candidate 2
- Python 3.13.0 release candidate 1
- Python 3.13.0 beta 4
- Python 3.13.0 beta 3
- Python 3.13.0 beta 2
- Python 3.13.0 beta 1
- Python 3.13.0 alpha 6
- Python 3.13.0 alpha 5
- Python 3.13.0 alpha 4
- Python 3.13.0 alpha 3
- Python 3.13.0 alpha 2
- Python 3.13.0 alpha 1
- Python 3.12.0 beta 1
- Python 3.12.0 alpha 7
- Python 3.12.0 alpha 6
- Python 3.12.0 alpha 5
- Python 3.12.0 alpha 4
- Python 3.12.0 alpha 3
- Python 3.12.0 alpha 2
- Python 3.12.0 alpha 1
- Python 3.11.0 beta 1
- Python 3.11.0 alpha 7
- Python 3.11.0 alpha 6
- Python 3.11.0 alpha 5
- Python 3.11.0 alpha 4
- Python 3.11.0 alpha 3
- Python 3.11.0 alpha 2
- Python 3.11.0 alpha 1
- Python 3.10.0 beta 1
- Python 3.10.0 alpha 7
- Python 3.10.0 alpha 6
- Python 3.10.0 alpha 5
- Python 3.10.0 alpha 4
- Python 3.10.0 alpha 3
- Python 3.10.0 alpha 2
- Python 3.10.0 alpha 1
- Python 3.9.0 beta 1
- Python 3.9.0 alpha 6
- Python 3.9.0 alpha 5
- Python 3.9.0 alpha 4
- Python 3.9.0 alpha 3
- Python 3.9.0 alpha 2
- Python 3.9.0 alpha 1
- Python 3.8.0 beta 1
- Python 3.8.0 alpha 4
- Python 3.8.0 alpha 3
- Python 3.8.0 alpha 2
- Python 3.8.0 alpha 1
- Python 3.7.0 final
- Python 3.7.0 release candidate 1
- Python 3.7.0 beta 5
- Python 3.7.0 beta 4
- Python 3.7.0 beta 3
- Python 3.7.0 beta 2
- Python 3.7.0 beta 1
- Python 3.7.0 alpha 4
- Python 3.7.0 alpha 3
- Python 3.7.0 alpha 2
- Python 3.7.0 alpha 1
- Python 3.6.6 final
- Python 3.6.6 release candidate 1
- Python 3.6.5 final
- Python 3.6.5 release candidate 1
- Python 3.6.4 final
- Python 3.6.4 release candidate 1
- Python 3.6.3 final
- Python 3.6.3 release candidate 1
- Python 3.6.2 final
- Python 3.6.2 release candidate 2
- Python 3.6.2 release candidate 1
- Python 3.6.1 final
- Python 3.6.1 release candidate 1
- Python 3.6.0 final
- Python 3.6.0 release candidate 2
- Python 3.6.0 release candidate 1
- Python 3.6.0 beta 4
- Python 3.6.0 beta 3
- Python 3.6.0 beta 2
- Python 3.6.0 beta 1
- Python 3.6.0 alpha 4
- Python 3.6.0 alpha 3
- Python 3.6.0 alpha 2
- Python 3.6.0 alpha 1
- Python 3.5.5 final
- Python 3.5.5 release candidate 1
- Python 3.5.4 final
- Python 3.5.4 release candidate 1
- Python 3.5.3 final
- Python 3.5.3 release candidate 1
- Python 3.5.2 final
- Python 3.5.2 release candidate 1
- Python 3.5.1 final
- Python 3.5.1 release candidate 1
- Python 3.5.0 final
- Python 3.5.0 release candidate 4
- Python 3.5.0 release candidate 3
- Python 3.5.0 release candidate 2
- Python 3.5.0 release candidate 1
- Python 3.5.0 beta 4
- Python 3.5.0 beta 3
- Python 3.5.0 beta 2
- Python 3.5.0 beta 1
- Python 3.5.0 alpha 4
- Python 3.5.0 alpha 3
- Python 3.5.0 alpha 2
- Python 3.5.0 alpha 1
- What’s New In Python 3.13
- The Python Tutorial
- 1. Whetting Your Appetite
- 2. Using the Python Interpreter
- 3. An Informal Introduction to Python
- 4. More Control Flow Tools
- 4.1.
if
Statements - 4.2.
for
Statements - 4.3. The
range()
Function - 4.4.
break
andcontinue
Statements - 4.5.
else
Clauses on Loops - 4.6.
pass
Statements - 4.7.
match
Statements - 4.8. Defining Functions
- 4.9. More on Defining Functions
- 4.10. Intermezzo: Coding Style
- 4.1.
- 5. Data Structures
- 6. Modules
- 7. Input and Output
- 8. Errors and Exceptions
- 9. Classes
- 10. Brief Tour of the Standard Library
- 10.1. Operating System Interface
- 10.2. File Wildcards
- 10.3. Command Line Arguments
- 10.4. Error Output Redirection and Program Termination
- 10.5. String Pattern Matching
- 10.6. Mathematics
- 10.7. Internet Access
- 10.8. Dates and Times
- 10.9. Data Compression
- 10.10. Performance Measurement
- 10.11. Quality Control
- 10.12. Batteries Included
- 11. Brief Tour of the Standard Library — Part II
- 12. Virtual Environments and Packages
- 13. What Now?
- 14. Interactive Input Editing and History Substitution
- 15. Floating-Point Arithmetic: Issues and Limitations
- 16. Appendix
- Python Setup and Usage
- 1. Command line and environment
- 2. Using Python on Unix platforms
- 3. Configure Python
- 3.1. Build Requirements
- 3.2. Generated files
- 3.3. Configure Options
- 3.3.1. General Options
- 3.3.2. C compiler options
- 3.3.3. Linker options
- 3.3.4. Options for third-party dependencies
- 3.3.5. WebAssembly Options
- 3.3.6. Install Options
- 3.3.7. Performance options
- 3.3.8. Python Debug Build
- 3.3.9. Debug options
- 3.3.10. Linker options
- 3.3.11. Libraries options
- 3.3.12. Security Options
- 3.3.13. macOS Options
- 3.3.14. iOS Options
- 3.3.15. Cross Compiling Options
- 3.4. Python Build System
- 3.5. Compiler and linker flags
- 4. Using Python on Windows
- 4.1. The full installer
- 4.2. The Microsoft Store package
- 4.3. The nuget.org packages
- 4.4. The embeddable package
- 4.5. Alternative bundles
- 4.6. Configuring Python
- 4.7. UTF-8 mode
- 4.8. Python Launcher for Windows
- 4.9. Finding modules
- 4.10. Additional modules
- 4.11. Compiling Python on Windows
- 4.12. Other Platforms
- 5. Using Python on macOS
- 6. Using Python on Android
- 7. Using Python on iOS
- 8. Editors and IDEs
- The Python Language Reference
- 1. Introduction
- 2. Lexical analysis
- 3. Data model
- 3.1. Objects, values and types
- 3.2. The standard type hierarchy
- 3.2.1. None
- 3.2.2. NotImplemented
- 3.2.3. Ellipsis
- 3.2.4.
numbers.Number
- 3.2.5. Sequences
- 3.2.6. Set types
- 3.2.7. Mappings
- 3.2.8. Callable types
- 3.2.9. Modules
- 3.2.10. Custom classes
- 3.2.11. Class instances
- 3.2.12. I/O objects (also known as file objects)
- 3.2.13. Internal types
- 3.3. Special method names
- 3.3.1. Basic customization
- 3.3.2. Customizing attribute access
- 3.3.3. Customizing class creation
- 3.3.4. Customizing instance and subclass checks
- 3.3.5. Emulating generic types
- 3.3.6. Emulating callable objects
- 3.3.7. Emulating container types
- 3.3.8. Emulating numeric types
- 3.3.9. With Statement Context Managers
- 3.3.10. Customizing positional arguments in class pattern matching
- 3.3.11. Emulating buffer types
- 3.3.12. Special method lookup
- 3.4. Coroutines
- 4. Execution model
- 5. The import system
- 6. Expressions
- 6.1. Arithmetic conversions
- 6.2. Atoms
- 6.3. Primaries
- 6.4. Await expression
- 6.5. The power operator
- 6.6. Unary arithmetic and bitwise operations
- 6.7. Binary arithmetic operations
- 6.8. Shifting operations
- 6.9. Binary bitwise operations
- 6.10. Comparisons
- 6.11. Boolean operations
- 6.12. Assignment expressions
- 6.13. Conditional expressions
- 6.14. Lambdas
- 6.15. Expression lists
- 6.16. Evaluation order
- 6.17. Operator precedence
- 7. Simple statements
- 7.1. Expression statements
- 7.2. Assignment statements
- 7.3. The
assert
statement - 7.4. The
pass
statement - 7.5. The
del
statement - 7.6. The
return
statement - 7.7. The
yield
statement - 7.8. The
raise
statement - 7.9. The
break
statement - 7.10. The
continue
statement - 7.11. The
import
statement - 7.12. The
global
statement - 7.13. The
nonlocal
statement - 7.14. The
type
statement
- 8. Compound statements
- 8.1. The
if
statement - 8.2. The
while
statement - 8.3. The
for
statement - 8.4. The
try
statement - 8.5. The
with
statement - 8.6. The
match
statement - 8.7. Function definitions
- 8.8. Class definitions
- 8.9. Coroutines
- 8.10. Type parameter lists
- 8.1. The
- 9. Top-level components
- 10. Full Grammar specification
- The Python Standard Library
- Introduction
- Built-in Functions
- Built-in Constants
- Built-in Types
- Truth Value Testing
- Boolean Operations —
and
,or
,not
- Comparisons
- Numeric Types —
int
,float
,complex
- Boolean Type -
bool
- Iterator Types
- Sequence Types —
list
,tuple
,range
- Text Sequence Type —
str
- Binary Sequence Types —
bytes
,bytearray
,memoryview
- Set Types —
set
,frozenset
- Mapping Types —
dict
- Context Manager Types
- Type Annotation Types — Generic Alias, Union
- Other Built-in Types
- Special Attributes
- Integer string conversion length limitation
- Built-in Exceptions
- Text Processing Services
string
— Common string operationsre
— Regular expression operationsdifflib
— Helpers for computing deltastextwrap
— Text wrapping and fillingunicodedata
— Unicode Databasestringprep
— Internet String Preparationreadline
— GNU readline interfacerlcompleter
— Completion function for GNU readline
- Binary Data Services
struct
— Interpret bytes as packed binary datacodecs
— Codec registry and base classes
- Data Types
datetime
— Basic date and time typeszoneinfo
— IANA time zone supportcalendar
— General calendar-related functionscollections
— Container datatypescollections.abc
— Abstract Base Classes for Containersheapq
— Heap queue algorithmbisect
— Array bisection algorithmarray
— Efficient arrays of numeric valuesweakref
— Weak referencestypes
— Dynamic type creation and names for built-in typescopy
— Shallow and deep copy operationspprint
— Data pretty printerreprlib
— Alternaterepr()
implementationenum
— Support for enumerationsgraphlib
— Functionality to operate with graph-like structures
- Numeric and Mathematical Modules
- Functional Programming Modules
- File and Directory Access
pathlib
— Object-oriented filesystem pathsos.path
— Common pathname manipulationsfileinput
— Iterate over lines from multiple input streamsstat
— Interpretingstat()
resultsfilecmp
— File and Directory Comparisonstempfile
— Generate temporary files and directoriesglob
— Unix style pathname pattern expansionfnmatch
— Unix filename pattern matchinglinecache
— Random access to text linesshutil
— High-level file operations
- Data Persistence
pickle
— Python object serializationcopyreg
— Registerpickle
support functionsshelve
— Python object persistencemarshal
— Internal Python object serializationdbm
— Interfaces to Unix “databases”sqlite3
— DB-API 2.0 interface for SQLite databases- Tutorial
- Reference
- How-to guides
- How to use placeholders to bind values in SQL queries
- How to adapt custom Python types to SQLite values
- How to convert SQLite values to custom Python types
- Adapter and converter recipes
- How to use connection shortcut methods
- How to use the connection context manager
- How to work with SQLite URIs
- How to create and use row factories
- How to handle non-UTF-8 text encodings
- Explanation
- Data Compression and Archiving
- File Formats
- Cryptographic Services
- Generic Operating System Services
os
— Miscellaneous operating system interfacesio
— Core tools for working with streamstime
— Time access and conversionsargparse
— Parser for command-line options, arguments and subcommandslogging
— Logging facility for Pythonlogging.config
— Logging configurationlogging.handlers
— Logging handlersgetpass
— Portable password inputcurses
— Terminal handling for character-cell displayscurses.textpad
— Text input widget for curses programscurses.ascii
— Utilities for ASCII characterscurses.panel
— A panel stack extension for cursesplatform
— Access to underlying platform’s identifying dataerrno
— Standard errno system symbolsctypes
— A foreign function library for Python- ctypes tutorial
- Loading dynamic link libraries
- Accessing functions from loaded dlls
- Calling functions
- Fundamental data types
- Calling functions, continued
- Calling variadic functions
- Calling functions with your own custom data types
- Specifying the required argument types (function prototypes)
- Return types
- Passing pointers (or: passing parameters by reference)
- Structures and unions
- Structure/union alignment and byte order
- Bit fields in structures and unions
- Arrays
- Pointers
- Type conversions
- Incomplete Types
- Callback functions
- Accessing values exported from dlls
- Surprises
- Variable-sized data types
- ctypes reference
- ctypes tutorial
- Concurrent Execution
threading
— Thread-based parallelismmultiprocessing
— Process-based parallelismmultiprocessing.shared_memory
— Shared memory for direct access across processes- The
concurrent
package concurrent.futures
— Launching parallel taskssubprocess
— Subprocess managementsched
— Event schedulerqueue
— A synchronized queue classcontextvars
— Context Variables_thread
— Low-level threading API
- Networking and Interprocess Communication
asyncio
— Asynchronous I/O- Runners
- Coroutines and Tasks
- Streams
- Synchronization Primitives
- Subprocesses
- Queues
- Exceptions
- Event Loop
- Event Loop Methods
- Running and stopping the loop
- Scheduling callbacks
- Scheduling delayed callbacks
- Creating Futures and Tasks
- Opening network connections
- Creating network servers
- Transferring files
- TLS Upgrade
- Watching file descriptors
- Working with socket objects directly
- DNS
- Working with pipes
- Unix signals
- Executing code in thread or process pools
- Error Handling API
- Enabling debug mode
- Running Subprocesses
- Callback Handles
- Server Objects
- Event Loop Implementations
- Examples
- Event Loop Methods
- Futures
- Transports and Protocols
- Policies
- Platform Support
- Extending
- High-level API Index
- Low-level API Index
- Developing with asyncio
socket
— Low-level networking interfacessl
— TLS/SSL wrapper for socket objectsselect
— Waiting for I/O completionselectors
— High-level I/O multiplexingsignal
— Set handlers for asynchronous eventsmmap
— Memory-mapped file support
- Internet Data Handling
email
— An email and MIME handling packageemail.message
: Representing an email messageemail.parser
: Parsing email messagesemail.generator
: Generating MIME documentsemail.policy
: Policy Objectsemail.errors
: Exception and Defect classesemail.headerregistry
: Custom Header Objectsemail.contentmanager
: Managing MIME Contentemail
: Examplesemail.message.Message
: Representing an email message using thecompat32
APIemail.mime
: Creating email and MIME objects from scratchemail.header
: Internationalized headersemail.charset
: Representing character setsemail.encoders
: Encodersemail.utils
: Miscellaneous utilitiesemail.iterators
: Iterators
json
— JSON encoder and decodermailbox
— Manipulate mailboxes in various formatsmimetypes
— Map filenames to MIME typesbase64
— Base16, Base32, Base64, Base85 Data Encodingsbinascii
— Convert between binary and ASCIIquopri
— Encode and decode MIME quoted-printable data
- Structured Markup Processing Tools
html
— HyperText Markup Language supporthtml.parser
— Simple HTML and XHTML parserhtml.entities
— Definitions of HTML general entities- XML Processing Modules
xml.etree.ElementTree
— The ElementTree XML APIxml.dom
— The Document Object Model APIxml.dom.minidom
— Minimal DOM implementationxml.dom.pulldom
— Support for building partial DOM treesxml.sax
— Support for SAX2 parsersxml.sax.handler
— Base classes for SAX handlersxml.sax.saxutils
— SAX Utilitiesxml.sax.xmlreader
— Interface for XML parsersxml.parsers.expat
— Fast XML parsing using Expat
- Internet Protocols and Support
webbrowser
— Convenient web-browser controllerwsgiref
— WSGI Utilities and Reference Implementationurllib
— URL handling modulesurllib.request
— Extensible library for opening URLs- Request Objects
- OpenerDirector Objects
- BaseHandler Objects
- HTTPRedirectHandler Objects
- HTTPCookieProcessor Objects
- ProxyHandler Objects
- HTTPPasswordMgr Objects
- HTTPPasswordMgrWithPriorAuth Objects
- AbstractBasicAuthHandler Objects
- HTTPBasicAuthHandler Objects
- ProxyBasicAuthHandler Objects
- AbstractDigestAuthHandler Objects
- HTTPDigestAuthHandler Objects
- ProxyDigestAuthHandler Objects
- HTTPHandler Objects
- HTTPSHandler Objects
- FileHandler Objects
- DataHandler Objects
- FTPHandler Objects
- CacheFTPHandler Objects
- UnknownHandler Objects
- HTTPErrorProcessor Objects
- Examples
- Legacy interface
urllib.request
Restrictions
urllib.response
— Response classes used by urlliburllib.parse
— Parse URLs into componentsurllib.error
— Exception classes raised by urllib.requesturllib.robotparser
— Parser for robots.txthttp
— HTTP moduleshttp.client
— HTTP protocol clientftplib
— FTP protocol clientpoplib
— POP3 protocol clientimaplib
— IMAP4 protocol clientsmtplib
— SMTP protocol clientuuid
— UUID objects according to RFC 4122socketserver
— A framework for network servershttp.server
— HTTP servershttp.cookies
— HTTP state managementhttp.cookiejar
— Cookie handling for HTTP clientsxmlrpc
— XMLRPC server and client modulesxmlrpc.client
— XML-RPC client accessxmlrpc.server
— Basic XML-RPC serversipaddress
— IPv4/IPv6 manipulation library
- Multimedia Services
- Internationalization
- Program Frameworks
turtle
— Turtle graphics- Introduction
- Get started
- Tutorial
- How to…
- Turtle graphics reference
- Methods of RawTurtle/Turtle and corresponding functions
- Methods of TurtleScreen/Screen and corresponding functions
- Public classes
- Explanation
- Help and configuration
turtledemo
— Demo scripts- Changes since Python 2.6
- Changes since Python 3.0
cmd
— Support for line-oriented command interpretersshlex
— Simple lexical analysis
- Graphical User Interfaces with Tk
tkinter
— Python interface to Tcl/Tktkinter.colorchooser
— Color choosing dialogtkinter.font
— Tkinter font wrapper- Tkinter Dialogs
tkinter.messagebox
— Tkinter message promptstkinter.scrolledtext
— Scrolled Text Widgettkinter.dnd
— Drag and drop supporttkinter.ttk
— Tk themed widgets- IDLE
- Development Tools
typing
— Support for type hints- Specification for the Python Type System
- Type aliases
- NewType
- Annotating callable objects
- Generics
- Annotating tuples
- The type of class objects
- Annotating generators and coroutines
- User-defined generic types
- The
Any
type - Nominal vs structural subtyping
- Module contents
- Deprecation Timeline of Major Features
pydoc
— Documentation generator and online help system- Python Development Mode
doctest
— Test interactive Python examplesunittest
— Unit testing frameworkunittest.mock
— mock object libraryunittest.mock
— getting started- Using Mock
- Mock Patching Methods
- Mock for Method Calls on an Object
- Mocking Classes
- Naming your mocks
- Tracking all Calls
- Setting Return Values and Attributes
- Raising exceptions with mocks
- Side effect functions and iterables
- Mocking asynchronous iterators
- Mocking asynchronous context manager
- Creating a Mock from an Existing Object
- Using side_effect to return per file content
- Patch Decorators
- Further Examples
- Mocking chained calls
- Partial mocking
- Mocking a Generator Method
- Applying the same patch to every test method
- Mocking Unbound Methods
- Checking multiple calls with mock
- Coping with mutable arguments
- Nesting Patches
- Mocking a dictionary with MagicMock
- Mock subclasses and their attributes
- Mocking imports with patch.dict
- Tracking order of calls and less verbose call assertions
- More complex argument matching
- Using Mock
test
— Regression tests package for Pythontest.support
— Utilities for the Python test suitetest.support.socket_helper
— Utilities for socket teststest.support.script_helper
— Utilities for the Python execution teststest.support.bytecode_helper
— Support tools for testing correct bytecode generationtest.support.threading_helper
— Utilities for threading teststest.support.os_helper
— Utilities for os teststest.support.import_helper
— Utilities for import teststest.support.warnings_helper
— Utilities for warnings tests
- Debugging and Profiling
- Software Packaging and Distribution
- Python Runtime Services
sys
— System-specific parameters and functionssys.monitoring
— Execution event monitoringsysconfig
— Provide access to Python’s configuration informationbuiltins
— Built-in objects__main__
— Top-level code environmentwarnings
— Warning controldataclasses
— Data Classescontextlib
— Utilities forwith
-statement contextsabc
— Abstract Base Classesatexit
— Exit handlerstraceback
— Print or retrieve a stack traceback__future__
— Future statement definitionsgc
— Garbage Collector interfaceinspect
— Inspect live objectssite
— Site-specific configuration hook
- Custom Python Interpreters
- Importing Modules
zipimport
— Import modules from Zip archivespkgutil
— Package extension utilitymodulefinder
— Find modules used by a scriptrunpy
— Locating and executing Python modulesimportlib
— The implementation ofimport
importlib.resources
– Package resource reading, opening and accessimportlib.resources.abc
– Abstract base classes for resourcesimportlib.metadata
– Accessing package metadata- The initialization of the
sys.path
module search path
- Python Language Services
ast
— Abstract Syntax Treessymtable
— Access to the compiler’s symbol tablestoken
— Constants used with Python parse treeskeyword
— Testing for Python keywordstokenize
— Tokenizer for Python sourcetabnanny
— Detection of ambiguous indentationpyclbr
— Python module browser supportpy_compile
— Compile Python source filescompileall
— Byte-compile Python librariesdis
— Disassembler for Python bytecodepickletools
— Tools for pickle developers
- MS Windows Specific Services
- Unix Specific Services
posix
— The most common POSIX system callspwd
— The password databasegrp
— The group databasetermios
— POSIX style tty controltty
— Terminal control functionspty
— Pseudo-terminal utilitiesfcntl
— Thefcntl
andioctl
system callsresource
— Resource usage informationsyslog
— Unix syslog library routines
- Modules command-line interface (CLI)
- Superseded Modules
getopt
— C-style parser for command line optionsoptparse
— Parser for command line options- Background
- Tutorial
- Reference Guide
- Option Callbacks
- Defining a callback option
- How callbacks are called
- Raising errors in a callback
- Callback example 1: trivial callback
- Callback example 2: check option order
- Callback example 3: check option order (generalized)
- Callback example 4: check arbitrary condition
- Callback example 5: fixed arguments
- Callback example 6: variable arguments
- Extending
optparse
- Exceptions
- Security Considerations
- Extending and Embedding the Python Interpreter
- Recommended third party tools
- Creating extensions without third party tools
- 1. Extending Python with C or C++
- 1.1. A Simple Example
- 1.2. Intermezzo: Errors and Exceptions
- 1.3. Back to the Example
- 1.4. The Module’s Method Table and Initialization Function
- 1.5. Compilation and Linkage
- 1.6. Calling Python Functions from C
- 1.7. Extracting Parameters in Extension Functions
- 1.8. Keyword Parameters for Extension Functions
- 1.9. Building Arbitrary Values
- 1.10. Reference Counts
- 1.11. Writing Extensions in C++
- 1.12. Providing a C API for an Extension Module
- 2. Defining Extension Types: Tutorial
- 3. Defining Extension Types: Assorted Topics
- 4. Building C and C++ Extensions
- 5. Building C and C++ Extensions on Windows
- 1. Extending Python with C or C++
- Embedding the CPython runtime in a larger application
- Python/C API Reference Manual
- Introduction
- C API Stability
- The Very High Level Layer
- Reference Counting
- Exception Handling
- Utilities
- Abstract Objects Layer
- Concrete Objects Layer
- Fundamental Objects
- Numeric Objects
- Sequence Objects
- Container Objects
- Function Objects
- Other Objects
- Initialization, Finalization, and Threads
- Before Python Initialization
- Global configuration variables
- Initializing and finalizing the interpreter
- Process-wide parameters
- Thread State and the Global Interpreter Lock
- Sub-interpreter support
- Asynchronous Notifications
- Profiling and Tracing
- Reference tracing
- Advanced Debugger Support
- Thread Local Storage Support
- Synchronization Primitives
- Python Initialization Configuration
- Memory Management
- Object Implementation Support
- API and ABI Versioning
- Monitoring C API
- Generating Execution Events
- Installing Python Modules
- Python HOWTOs
- Python Frequently Asked Questions
- General Python FAQ
- Programming FAQ
- Design and History FAQ
- Why does Python use indentation for grouping of statements?
- Why am I getting strange results with simple arithmetic operations?
- Why are floating-point calculations so inaccurate?
- Why are Python strings immutable?
- Why must ‘self’ be used explicitly in method definitions and calls?
- Why can’t I use an assignment in an expression?
- Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?
- Why is join() a string method instead of a list or tuple method?
- How fast are exceptions?
- Why isn’t there a switch or case statement in Python?
- Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?
- Why can’t lambda expressions contain statements?
- Can Python be compiled to machine code, C or some other language?
- How does Python manage memory?
- Why doesn’t CPython use a more traditional garbage collection scheme?
- Why isn’t all memory freed when CPython exits?
- Why are there separate tuple and list data types?
- How are lists implemented in CPython?
- How are dictionaries implemented in CPython?
- Why must dictionary keys be immutable?
- Why doesn’t list.sort() return the sorted list?
- How do you specify and enforce an interface spec in Python?
- Why is there no goto?
- Why can’t raw strings (r-strings) end with a backslash?
- Why doesn’t Python have a “with” statement for attribute assignments?
- Why don’t generators support the with statement?
- Why are colons required for the if/while/def/class statements?
- Why does Python allow commas at the end of lists and tuples?
- Library and Extension FAQ
- Extending/Embedding FAQ
- Can I create my own functions in C?
- Can I create my own functions in C++?
- Writing C is hard; are there any alternatives?
- How can I execute arbitrary Python statements from C?
- How can I evaluate an arbitrary Python expression from C?
- How do I extract C values from a Python object?
- How do I use Py_BuildValue() to create a tuple of arbitrary length?
- How do I call an object’s method from C?
- How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?
- How do I access a module written in Python from C?
- How do I interface to C++ objects from Python?
- I added a module using the Setup file and the make fails; why?
- How do I debug an extension?
- I want to compile a Python module on my Linux system, but some files are missing. Why?
- How do I tell “incomplete input” from “invalid input”?
- How do I find undefined g++ symbols __builtin_new or __pure_virtual?
- Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?
- Python on Windows FAQ
- How do I run a Python program under Windows?
- How do I make Python scripts executable?
- Why does Python sometimes take so long to start?
- How do I make an executable from a Python script?
- Is a
*.pyd
file the same as a DLL? - How can I embed Python into a Windows application?
- How do I keep editors from inserting tabs into my Python source?
- How do I check for a keypress without blocking?
- How do I solve the missing api-ms-win-crt-runtime-l1-1-0.dll error?
- Graphic User Interface FAQ
- “Why is Python Installed on my Computer?” FAQ
- Deprecations
- Glossary
- About these documents
- Dealing with Bugs
- Copyright
- History and License
- History of the software
- Terms and conditions for accessing or otherwise using Python
- Licenses and Acknowledgements for Incorporated Software
- Mersenne Twister
- Sockets
- Asynchronous socket services
- Cookie management
- Execution tracing
- UUencode and UUdecode functions
- XML Remote Procedure Calls
- test_epoll
- Select kqueue
- SipHash24
- strtod and dtoa
- OpenSSL
- expat
- libffi
- zlib
- cfuhash
- libmpdec
- W3C C14N test suite
- mimalloc
- asyncio
- Global Unbounded Sequences (GUS)