Changelog¶
Python next¶
Release date: XXXX-XX-XX
Core and Builtins¶
gh-92804: Fix memory leak in
memoryview
iterator as it was not finalized at exit. Patch by Kumar Aditya.gh-92236: Remove spurious “LINE” event when starting a generator or coroutine, visible tracing functions implemented in C.
gh-92619: Make the compiler duplicate an exit block only if none of its instructions have a lineno (previously only the first instruction in the block was checked, leading to unnecessarily duplicated blocks).
gh-92261: Fix hang when trying to iterate over a
typing.Union
.
Library¶
gh-90473:
subprocess
now fails early on Emscripten and WASI platforms to work around missingos.pipe()
on WASI.gh-92671: Fixed
ast.unparse()
for empty tuples in the assignment target context.gh-91581:
utcfromtimestamp()
no longer attempts to resolvefold
in the pure Python implementation, since the fold is never 1 in UTC. In addition to being slightly faster in the common case, this also prevents some errors when the timestamp is close todatetime.min
. Patch by Paul Ganssle.gh-92550: Fix
pathlib.Path.rglob()
for empty pattern.gh-92530: Fix an issue that occurred after interrupting
threading.Condition.notify()
.gh-92531: The statistics.median_grouped() function now always return a float. Formerly, it did not convert the input type when for sequences of length one.
gh-91810:
ElementTree
methodwrite()
and functiontostring()
now use the text file’s encoding (“UTF-8” if not available) instead of locale encoding in XML declaration whenencoding="unicode"
is specified.gh-90622: Worker processes for
concurrent.futures.ProcessPoolExecutor
are no longer spawned on demand (a feature added in 3.9) when the multiprocessing context start method is"fork"
as that can lead to deadlocks in the child processes due to a fork happening while threads are running.gh-91581: Remove an unhandled error case in the C implementation of calls to
datetime.fromtimestamp
with no time zone (i.e. getting a local time from an epoch timestamp). This should have no user-facing effect other than giving a possibly more accurate error message when called with timestamps that fall on 10000-01-01 in the local time. Patch by Paul Ganssle.bpo-45046: Add support of context managers in
unittest
: methodsenterContext()
andenterClassContext()
of classTestCase
, methodenterAsyncContext()
of classIsolatedAsyncioTestCase
and functionunittest.enterModuleContext()
.bpo-42627: Fix incorrect parsing of Windows registry proxy settings
Documentation¶
bpo-40838: Document that
inspect.getdoc()
,inspect.getmodule()
, andinspect.getsourcefile()
might returnNone
.bpo-38056: Overhaul the Error Handlers documentation in
codecs
.bpo-13553: Document tkinter.Tk args.
Build¶
gh-90473: Disable pymalloc and increase stack size on
wasm32-wasi
.
Windows¶
C API¶
gh-92781: Avoid mixing declarations and code in the C API to fix the compiler warning: “ISO C90 forbids mixed declarations and code” [-Werror=declaration-after-statement]. Patch by Victor Stinner.
Python 3.11.0 beta 1¶
Release date: 2022-05-06
Security¶
gh-57684: Add the
-P
command line option and thePYTHONSAFEPATH
environment variable to not prepend a potentially unsafe path tosys.path
. Patch by Victor Stinner.
Core and Builtins¶
gh-89519: Chaining classmethod descriptors (introduced in bpo-19072) is deprecated. It can no longer be used to wrap other descriptors such as property(). The core design of this feature was flawed, and it caused a number of downstream problems.
gh-92345:
pymain_run_python()
now importsreadline
andrlcompleter
before sys.path is extended to include the current working directory of an interactive interpreter. Non-interactive interpreters are not affected.bpo-43857: Improve the
AttributeError
message when deleting a missing attribute. Patch by Géry Ogam.gh-92245: Make sure that PEP 523 is respected in all cases. In 3.11a7, specialization may have prevented Python-to-Python calls respecting PEP 523.
gh-92203: Add a closure keyword-only parameter to exec(). It can only be specified when exec-ing a code object that uses free variables. When specified, it must be a tuple, with exactly the number of cell variables referenced by the code object. closure has a default value of None, and it must be None if the code object doesn’t refer to any free variables.
gh-91173: Disable frozen modules in debug builds. Patch by Kumar Aditya.
gh-92114: Improve error message when subscript a type with
__class_getitem__
set toNone
.gh-92112: Fix crash triggered by an evil custom
mro()
on a metaclass.gh-92063: The
PRECALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS
instruction now ensures methods are called only on objects of the correct type.gh-92031: Deoptimize statically-allocated code objects during
Py_FINALIZE()
so that future_PyCode_Quicken
calls always start with unquickened code.gh-92036: Fix a crash in subinterpreters related to the garbage collector. When a subinterpreter is deleted, untrack all objects tracked by its GC. To prevent a crash in deallocator functions expecting objects to be tracked by the GC, leak a strong reference to these objects on purpose, so they are never deleted and their deallocator functions are not called. Patch by Victor Stinner.
gh-92032: The interpreter can now autocomplete soft keywords, as of now
match
,case
, and_
(wildcard pattern) from PEP 634.gh-87999: The warning emitted by the Python parser for a numeric literal immediately followed by keyword has been changed from deprecation warning to syntax warning.
gh-91869: Fix an issue where specialized opcodes with extended arguments could produce incorrect tracing output or lead to assertion failures.
gh-91603: Speed up
types.UnionType
instantiation. Based on patch provided by Yurii Karabas.gh-89373: If Python is built in debug mode, Python now ensures that deallocator functions leave the current exception unchanged. Patch by Victor Stinner.
gh-91632: Fix a minor memory leak at exit: release the memory of the
generic_alias_iterator
type. Patch by Dong-hee Na.gh-81548: Octal escapes with value larger than
0o377
now produce aDeprecationWarning
. In a future Python version they will be aSyntaxWarning
and eventually aSyntaxError
.bpo-43950: Use a single compact table for line starts, ends and column offsets. Reduces memory consumption for location info by half
gh-91102: Use Argument Clinic for
EncodingMap
. Patch by Oleg Iarygin.gh-91636: Fixed a crash in a garbage-collection edge-case, in which a
PyFunction_Type.tp_clear
function could leave a python function object in an inconsistent state.gh-91603: Speed up
isinstance()
andissubclass()
checks fortypes.UnionType
. Patch by Yurii Karabas.gh-91625: Fixed a bug in which adaptive opcodes ignored any preceding
EXTENDED_ARG
s on specialization failure.gh-78607: The LLTRACE special build now looks for the name
__lltrace__
defined in module globals, rather than the name__ltrace__
, which had been introduced as a typo.gh-91576: Speed up iteration of ascii strings by 50%. Patch by Kumar Aditya.
gh-89279: Improve interpreter performance on Windows by inlining a few specific macros.
gh-91502: Add a new
_PyFrame_IsEntryFrame()
API function, to check if aPyFrameObject
is an entry frame. Patch by Pablo Galindo.gh-91266: Refactor the
bytearray
strip methodsstrip
,lstrip
andrstrip
to use a common implementation.gh-91479: Replaced the
__note__
field ofBaseException
(added in an earlier version of 3.11) with the final design of PEP 678. Namely,BaseException
gets anadd_note()
method, and its__notes__
field is created when necessary.gh-46055: Speed up right shift of negative integers, by removing unnecessary creation of temporaries. Original patch by Xinhang Xu, reworked by Mark Dickinson.
gh-91462: Make the interpreter’s low-level tracing (lltrace) feature output more readable by displaying opcode names (rather than just numbers), and by displaying stack contents before each opcode.
gh-89455: Fixed an uninitialized bool value in the traceback printing code path that was introduced by the initial bpo-45292 exception groups work.
gh-91421: Fix a potential integer overflow in _Py_DecodeUTF8Ex.
gh-91428: Add
static const char *const _PyOpcode_OpName[256] = {...};
toopcode.h
for debug builds to assist in debugging the Python interpreter. It is now more convenient to make various forms of debugging output more human-readable by including opcode names rather than just the corresponding decimal digits.bpo-47120: Make
POP_JUMP_IF_TRUE
,POP_JUMP_IF_FALSE
,POP_JUMP_IF_NONE
andPOP_JUMP_IF_NOT_NONE
virtual, mapping to new relative jump opcodes.bpo-45317: Add internal documentation explaining design of new (for 3.11) frame stack.
bpo-47197: ctypes used to mishandle
void
return types, so that for instance a function declared likectypes.CFUNCTYPE(None, ctypes.c_int)
would be called with signatureint f(int)
instead ofvoid f(int)
. Wasm targets require function pointers to be called with the correct signatures so this led to crashes. The problem is now fixed.bpo-47120: Make opcodes
JUMP_IF_TRUE_OR_POP
andJUMP_IF_FALSE_OR_POP
relative rather than absolute.bpo-47177: Replace the
f_lasti
member of the internal_PyInterpreterFrame
structure with aprev_instr
pointer, which reduces overhead in the main interpreter loop. Thef_lasti
attribute of Python-layer frame objects is preserved for backward-compatibility.bpo-46961: Integer mod/remainder operations, including the three-argument form of
pow()
, now consistently return ints from the global small integer cache when applicable.bpo-46962: Classes and functions that unconditionally declared their docstrings ignoring the
--without-doc-strings
compilation flag no longer do so.The classes affected are
ctypes.UnionType
,pickle.PickleBuffer
,testcapi.RecursingInfinitelyError
, andtypes.GenericAlias
.The functions affected are 24 methods in
ctypes
.Patch by Oleg Iarygin.
bpo-46942: Use Argument Clinic for the
types.MethodType
constructor. Patch by Oleg Iarygin.bpo-46764: Fix wrapping bound methods with @classmethod
bpo-43464: Optimize
set.intersection()
for non-set arguments.bpo-46721: Optimize
set.issuperset()
for non-set argument.bpo-46509: Add type-specialized versions of the
Py_DECREF()
, and use them forfloat
,int
,str
,bool
, andNone
to avoid pointer-chasing at runtime where types are known at C compile time.bpo-46045: Do not use POSIX semaphores on NetBSD
bpo-36819: Fix crashes in built-in encoders with error handlers that return position less or equal than the starting position of non-encodable characters.
bpo-34093:
marshal.dumps()
usesFLAG_REF
for all interned strings. This makes output more deterministic and helps reproducible build.bpo-26579: Added
object.__getstate__
which provides the default implementation of the__getstate__()
method.Copying and pickling instances of subclasses of builtin types bytearray, set, frozenset, collections.OrderedDict, collections.deque, weakref.WeakSet, and datetime.tzinfo now copies and pickles instance attributes implemented as slots.
Library¶
gh-87901: Add the encoding parameter to
os.popen()
.gh-90997: Fix an issue where
dis
utilities may interpret populated inline cache entries as valid instructions.gh-92332: Deprecate
typing.Text
(removal of the class is currently not planned). Patch by Alex Waygood.Deprecate nested classes in enum definitions becoming members – in 3.13 they will be normal classes; add
member
andnonmember
functions to allow control over results now.gh-92356: Fixed a performance regression in ctypes function calls.
gh-90997: Show the actual named values stored in inline caches when
show_caches=True
is passed todis
utilities.gh-92301: Prefer
close_range()
to iterating over procfs for file descriptor closing insubprocess
for better performance.gh-67248: Sort the miscellaneous topics in Cmd.do_help()
gh-92210: Port
socket.__init__
to Argument Clinic. Patch by Cinder.gh-80010: Add support for generalized ISO 8601 parsing to
datetime.datetime.fromisoformat()
,datetime.date.fromisoformat()
anddatetime.time.fromisoformat()
. Patch by Paul Ganssle.gh-92118: Fix a 3.11 regression in
contextmanager()
, which caused it to propagate exceptions with incorrect tracebacks.gh-90887: Adding
COPYFILE_STAT
,COPYFILE_ACL
andCOPYFILE_XATTR
constants foros.fcopyfile()
available in macOs.gh-91215: For @dataclass, add weakref_slot. Default is False. If True, and if slots=True, add a slot named “__weakref__”, which will allow instances to be weakref’d. Contributed by Eric V. Smith
gh-85984: New function os.login_tty() for Unix.
gh-92128: Add
__class_getitem__()
tologging.LoggerAdapter
andlogging.StreamHandler
, allowing them to be parameterized at runtime. Patch by Alex Waygood.gh-92049: Forbid pickling constants
re._constants.SUCCESS
etc. Previously, pickling did not fail, but the result could not be unpickled.gh-92062:
inspect.Parameter
now raisesValueError
ifname
is a keyword, in addition to the existing check that it is an identifier.gh-87390: Add an
__unpacked__
attribute totypes.GenericAlias
. Patch by Jelle Zijlstra.gh-88089: Add support for generic
typing.NamedTuple
.gh-91996: New http.HTTPMethod enum to represent all the available HTTP request methods in a convenient way
gh-91984: Modified test strings in test_argparse.py to not contain trailing spaces before end of line.
gh-91952: Add
encoding="locale"
support toTextIOWrapper.reconfigure()
.gh-91954: Add encoding and errors arguments to
subprocess.getoutput()
andsubprocess.getstatusoutput()
.bpo-47029: Always close the read end of the pipe used by
multiprocessing.Queue
after the last write of buffered data to the write end of the pipe to avoidBrokenPipeError
at garbage collection and atmultiprocessing.Queue.close()
calls. Patch by Géry Ogam.gh-91928: Add
datetime.UTC
alias fordatetime.timezone.utc
.Patch by Kabir Kwatra.
gh-68966: The
mailcap
module is now deprecated and will be removed in Python 3.13. See PEP 594 for the rationale and themimetypes
module for an alternative. Patch by Victor Stinner.gh-91401: Provide a way to disable
subprocess
use ofvfork()
just in case it is ever needed and document the existing mechanism forposix_spawn()
.gh-64783: Fix
signal.NSIG
value on FreeBSD to accept signal numbers greater than 32, likesignal.SIGRTMIN
andsignal.SIGRTMAX
. Patch by Victor Stinner.gh-91910: Add missing f prefix to f-strings in error messages from the
multiprocessing
andasyncio
modules.gh-91860: Add
typing.dataclass_transform()
, implementing PEP 681. Patch by Jelle Zijlstra.gh-91832: Add
required
attribute toargparse.Action
repr output.gh-91827: In the
tkinter
module add methodinfo_patchlevel()
which returns the exact version of the Tcl library as a named tuple similar tosys.version_info
.gh-84461: Add
--enable-wasm-pthreads
to enable pthreads support for WASM builds.Emscripten/node
no longer has threading enabled by default. Include additional file systems.gh-91821: Fix unstable
test_from_tuple
test intest_decimal.py
.gh-91217: Deprecate the xdrlib module.
gh-91217: Deprecate the uu module.
gh-91760: More strict rules will be applied for numerical group references and group names in regular expressions. For now, a deprecation warning is emitted for group references and group names which will be errors in future Python versions.
gh-84461: Add provisional
sys._emscripten_info
named tuple with build-time and run-time information about Emscripten platform.gh-90623:
signal.raise_signal()
andos.kill()
now check immediately for pending signals. Patch by Victor Stinner.gh-91734: Fix OSS audio support on Solaris.
gh-90633: Include the passed value in the exception thrown by
typing.assert_never()
. Patch by Jelle Zijlstra.gh-91700: Compilation of regular expression containing a conditional expression
(?(group)...)
now raises an appropriatere.error
if the group number refers to not defined group. Previously an internal RuntimeError was raised.gh-91231: Add an optional keyword shutdown_timeout parameter to the
multiprocessing.BaseManager
constructor. Kill the process if terminate() takes longer than the timeout. Patch by Victor Stinner.gh-91621: Fix
typing.get_type_hints()
forcollections.abc.Callable
. Patch by Shantanu Jain.gh-90568: Parsing
\N
escapes of Unicode Named Character Sequences in aregular expression
raises nowre.error
instead ofTypeError
.gh-91670: Remove deprecated
SO
config variable insysconfig
.gh-91217: Deprecate the telnetlib module.
gh-91217: Deprecate the sunau module.
gh-91217: Deprecate the spwd module.
gh-91217: Deprecate the sndhdr module, as well as inline needed functionality for
email.mime.MIMEAudio
.gh-91616:
re
module, fixfullmatch()
mismatch when using Atomic Grouping or Possessive Quantifiers.gh-91217: Deprecate the ‘pipes’ module.
gh-91217: Deprecate the ossaudiodev module.
bpo-47256:
re
module, limit the maximum capturing group to 1,073,741,823 in 64-bit build, this increases the depth of backtracking.gh-91217: Deprecate the nis module.
gh-91595: Fix the comparison of character and integer inside
Tools.gdb.libpython.write_repr()
. Patch by Yu Liu.gh-74166: Add option to raise all errors from
create_connection()
in anExceptionGroup
when it fails to create a connection. The default remains to raise only the last error that had occurred when multiple addresses were tried.gh-91487: Optimize asyncio UDP speed, over 100 times faster when transferring a large file.
gh-91575: Update case-insensitive matching in the
re
module to the latest Unicode version.gh-90622: In
concurrent.futures.process.ProcessPoolExecutor
disallow the “fork” multiprocessing start method when the newmax_tasks_per_child
feature is used as the mix of threads+fork can hang the child processes. Default to using the safe “spawn” start method in that circumstance if nomp_context
was supplied.gh-89022: In
sqlite3
,SQLITE_MISUSE
result codes are now mapped toInterfaceError
instead ofProgrammingError
. Also, more accurate exceptions are raised when binding parameters fail. Patch by Erlend E. Aasland.gh-91526: Stop calling
os.device_encoding(file.fileno())
inTextIOWrapper
. It was complex, never documented, and didn’t work for most cases. (Patch by Inada Naoki.)gh-88116: Change the frame-related functions in the
inspect
module to return a regular object (that is backwards compatible with the old tuple-like interface) that include the extended PEP 657 position information (end line number, column and end column). The affected functions are:inspect.getframeinfo()
,inspect.getouterframes()
,inspect.getinnerframes()
,inspect.stack()
andinspect.trace()
. Patch by Pablo Galindo.gh-69093: Add indexing and slicing support to
sqlite3.Blob
. Patch by Aviv Palivoda and Erlend E. Aasland.gh-69093: Add context manager support to
sqlite3.Blob
. Patch by Aviv Palivoda and Erlend E. Aasland.gh-91217: Deprecate nntplib.
gh-91217: Deprecate msilib.
gh-91404: Improve the performance of
re
matching by using computed gotos (or “threaded code”) on supported platforms and removing expensive pointer indirections.gh-91217: Deprecate the imghdr module.
gh-91217: Deprecate the crypt module.
bpo-47000: Make
TextIOWrapper
uses locale encoding whenencoding="locale"
is specified even in UTF-8 mode.gh-91230:
warnings.catch_warnings()
now accepts arguments forwarnings.simplefilter()
, providing a more concise way to locally ignore warnings or convert them to errors.gh-91217: Deprecate the chunk module.
Add the
TCP_CONNECTION_INFO
option (available on macOS) tosocket
.bpo-47260: Fix
os.closerange()
potentially being a no-op in a Linux seccomp sandbox.bpo-47087: Implement
typing.Required
andtyping.NotRequired
(PEP 655). Patch by David Foster and Jelle Zijlstra.bpo-47061: Deprecate cgi and cgitb.
bpo-47061: Deprecate audioop.
bpo-47000: Add
locale.getencoding()
to get the current locale encoding. It is similar tolocale.getpreferredencoding(False)
but ignores the Python UTF-8 Mode.bpo-42012: Add
wsgiref.types
, containing WSGI-specific types for static type checking.bpo-47227: Suppress expression chaining for more
re
parsing errors.bpo-47211: Remove undocumented and never working function
re.template()
and flagre.TEMPLATE
.bpo-47135:
decimal.localcontext()
now accepts context attributes via keyword argumentsbpo-43323: Fix errors in the
email
module if the charset itself contains undecodable/unencodable characters.bpo-46841: Disassembly of quickened code.
bpo-46681: Forward gzip.compress() compresslevel to zlib.
bpo-45100: Add
typing.get_overloads()
andtyping.clear_overloads()
. Patch by Jelle Zijlstra.bpo-44807:
typing.Protocol
no longer silently replaces__init__()
methods defined on subclasses. Patch by Adrian Garcia Badaracco.bpo-46787: Fix
concurrent.futures.ProcessPoolExecutor
exception memory leakbpo-46720: Add support for path-like objects to
multiprocessing.set_executable()
for Windows to be on a par with Unix-like systems. Patch by Géry Ogam.bpo-46053: Fix OSS audio support on NetBSD.
bpo-45639:
image/avif
andimage/webp
were added tomimetypes
.bpo-46285: Add command-line option
-p
/--protocol
to modulehttp.server
which specifies the HTTP version to which the server is conformant (HTTP/1.1 conformant servers can now be run from the command-line interface of modulehttp.server
). Patch by Géry Ogam.bpo-44791: Accept ellipsis as the last argument of
typing.Concatenate
.bpo-46547: Remove variables leaking into
pydoc.Helper
class namespace.bpo-46415: Fix ipaddress.ip_{address,interface,network} raising TypeError instead of ValueError if given invalid tuple as address parameter.
bpo-46075:
CookieJar
withDefaultCookiePolicy
now can process cookies from localhost with domain=localhost explicitly specified in Set-Cookie header.bpo-45995: Add a “z” option to the string formatting specification that coerces negative zero floating-point values to positive zero after rounding to the format precision. Contributed by John Belmonte.
bpo-26175: Fully implement the
io.BufferedIOBase
orio.TextIOBase
interface fortempfile.SpooledTemporaryFile
objects. This lets them work correctly with higher-level layers (like compression modules). Patch by Carey Metcalfe.bpo-45138: Fix a regression in the
sqlite3
trace callback where bound parameters were not expanded in the passed statement string. The regression was introduced in Python 3.10 by bpo-40318. Patch by Erlend E. Aasland.bpo-44863: Allow
TypedDict
subclasses to also includeGeneric
as a base class in class based syntax. Thereby allowing the user to define a genericTypedDict
, just like a user-defined generic but withTypedDict
semantics.bpo-44587: Fix BooleanOptionalAction to not automatically add a default string. If a default string is desired, use a formatter to add it.
bpo-43827: All positional-or-keyword parameters to
ABCMeta.__new__
are now positional-only to avoid conflicts with keyword arguments to be passed to__init_subclass__()
.bpo-43218: Prevent creation of a venv whose path contains the PATH separator. This could affect the usage of the activate script. Patch by Dustin Rodrigues.
bpo-38435: Add a
process_group
parameter tosubprocess.Popen
to help move more things off of the unsafepreexec_fn
parameter.bpo-42066: Fix cookies getting sorted in
CookieJar.__iter__()
which is an extra behavior and not mentioned in RFC 2965 or Netscape cookie protocol. Now the cookies inCookieJar
follows the order of theSet-Cookie
header. Patch by Iman Kermani.bpo-40617: Add
create_window_function()
tosqlite3.Connection
for creating aggregate window functions. Patch by Erlend E. Aasland.bpo-40676: Convert
csv
to use Argument Clinic forcsv.field_size_limit()
,csv.get_dialect()
,csv.unregister_dialect()
andcsv.list_dialects()
.bpo-39716: Raise an ArgumentError when the same subparser name is added twice to an
argparse.ArgumentParser
. This is consistent with the (default) behavior when the same option string is added twice to an ArgumentParser.bpo-36073: Raise
ProgrammingError
instead of segfaulting on recursive usage of cursors insqlite3
converters. Patch by Sergey Fedoseev.bpo-34975: Adds a
start_tls()
method toStreamWriter
, which upgrades the connection with TLS using the givenSSLContext
.bpo-22276:
Path
methodsglob()
andrglob()
return only directories if pattern ends with a pathname components separator (/
orsep
). Patch by Eisuke Kawashima.bpo-24905: Add
blobopen()
tosqlite3.Connection
.sqlite3.Blob
allows incremental I/O operations on blobs. Patch by Aviv Palivoda and Erlend E. Aasland.
Documentation¶
gh-91888: Add a new
gh
role to the documentation to link to GitHub issues.gh-91783: Document security issues concerning the use of the function
shutil.unpack_archive()
gh-91547: Remove “Undocumented modules” page.
gh-91298: In
importlib.resources.abc
, refined the documentation of the Traversable Protocol, applying changes from importlib_resources 5.7.1.bpo-44347: Clarify the meaning of dirs_exist_ok, a kwarg of
shutil.copytree()
.bpo-36329: Remove ‘make -C Doc serve’ in favour of ‘make -C Doc htmlview’
bpo-47189: Add a What’s New in Python 3.11 entry for the Faster CPython project. Documentation by Ken Jin and Kumar Aditya.
bpo-38668: Update the introduction to documentation for
os.path
to remove warnings that became irrelevant after the implementations of PEP 383 and PEP 529.bpo-47115: The documentation now lists which members of C structs are part of the Limited API/Stable ABI.
bpo-46962: All docstrings in code snippets are now wrapped into
PyDoc_STR()
to follow the guideline of PEP 7’s Documentation Strings paragraph. Patch by Oleg Iarygin.bpo-26792: Improve the docstrings of
runpy.run_module()
andrunpy.run_path()
. Original patch by Andrew Brezovsky.
Tests¶
gh-92169: Use
warnings_helper.import_deprecated()
to import deprecated modules uniformly in tests. Patch by Hugo van Kemenade.gh-84461: When multiprocessing is enabled, libregrtest can now use a Python executable other than
sys.executable
via the--python
flag.gh-91904: Fix initialization of
PYTHONREGRTEST_UNICODE_GUARD
which prevented running regression tests on non-UTF-8 locale.gh-91752: Added @requires_zlib to test.test_tools.test_freeze.TestFreeze.
gh-91607: Fix
test_concurrent_futures
to test the correct multiprocessing start method context in several cases where the test logic mixed this up.bpo-40280: Threading tests are now skipped on WASM targets without pthread support.
bpo-47109: Test for
ctypes.macholib.dyld
,ctypes.macholib.dylib
, andctypes.macholib.framework
are brought from manual pre-unittest
times toctypes.test
location and structure. Patch by Oleg Iarygin.bpo-29890: Add tests for
ipaddress.IPv4Interface
andipaddress.IPv6Interface
construction with tuple arguments. Original patch and tests by louisom.
Build¶
gh-89452: gdbm-compat is now preferred over ndbm if both are available on the system. This allows avoiding the problematic ndbm.h on macOS.
gh-91731: Python is now built with
-std=c11
compiler option, rather than-std=c99
. Patch by Victor Stinner.bpo-47152: Add script and make target for generating
sre_constants.h
.bpo-47103: Windows
PGInstrument
builds now copy a required DLL into the output directory, making it easier to run the profile stage of a PGO build.
Windows¶
bpo-46907: Update Windows installer to use SQLite 3.38.3.
bpo-47239: Fixed –list and –list-paths output for Python Launcher for Windows when used in an active virtual environment.
bpo-46907: Update Windows installer to use SQLite 3.38.2.
bpo-46785: Fix race condition between
os.stat()
and unlinking a file on Windows, by using errors codes returned byFindFirstFileW()
when appropriate inwin32_xstat_impl
.bpo-40859: Update Windows build to use xz-5.2.5
macOS¶
bpo-46907: Update macOS installer to SQLite 3.38.4.
Tools/Demos¶
gh-91583: Fix regression in the code generated by Argument Clinic for functions with the
defining_class
parameter.gh-91575: Add script
Tools/scripts/generate_re_casefix.py
and the make targetregen-re
for generating additional data for case-insensitive matching according to the current Unicode version.gh-91551: Remove the ancient Pynche color editor. It has moved to https://gitlab.com/warsaw/pynche
C API¶
gh-88279: Deprecate the C functions:
PySys_SetArgv()
,PySys_SetArgvEx()
,PySys_SetPath()
. Patch by Victor Stinner.gh-92154: Added the
PyCode_GetCode()
function. This function does the equivalent of the Python codegetattr(code_object, 'co_code')
.gh-92173: Fix the
closure
argument toPyEval_EvalCodeEx()
.gh-91320: Fix C++ compiler warnings about “old-style cast” (
g++ -Wold-style-cast
) in the Python C API. Use C++reinterpret_cast<>
andstatic_cast<>
casts when the Python C API is used in C++. Patch by Victor Stinner.gh-80527: Mark functions as deprecated by PEP 623:
PyUnicode_AS_DATA()
,PyUnicode_AS_UNICODE()
,PyUnicode_GET_DATA_SIZE()
,PyUnicode_GET_SIZE()
. Patch by Victor Stinner.gh-91768:
Py_REFCNT()
,Py_TYPE()
,Py_SIZE()
andPy_IS_TYPE()
functions argument type is nowPyObject*
, rather thanconst PyObject*
. Patch by Victor Stinner.gh-91020: Add
PyBytes_Type.tp_alloc
to initializePyBytesObject.ob_shash
for bytes subclasses.bpo-40421: Add
PyFrame_GetLasti
C-API function to access frame object’sf_lasti
attribute safely from C code.bpo-35134: Remove the
Include/code.h
header file. C extensions should only include the main<Python.h>
header file. Patch by Victor Stinner.bpo-47169:
PyOS_CheckStack()
is now exported in the Stable ABI on Windows.bpo-47169:
PyThread_get_thread_native_id()
is excluded from the stable ABI on platforms where it doesn’t exist (like Solaris).bpo-46343: Added
PyErr_GetHandledException()
andPyErr_SetHandledException()
as simpler alternatives toPyErr_GetExcInfo()
andPyErr_SetExcInfo()
.They are included in the stable ABI.
Python 3.11.0 alpha 7¶
Release date: 2022-04-05
Core and Builtins¶
bpo-47212: Raise
IndentationError
instead ofSyntaxError
for a bareexcept
with no following indent. ImproveSyntaxError
locations for an un-parenthesized generator used as arguments. Patch by Matthieu Dartiailh.bpo-47186: Replace
JUMP_IF_NOT_EG_MATCH
byCHECK_EG_MATCH
+ jump.bpo-47176: Emscripten builds cannot handle signals in the usual way due to platform limitations. Python can now handle signals. To use, set Module.Py_EmscriptenSignalBuffer to be a single byte SharedArrayBuffer and set Py_EMSCRIPTEN_SIGNAL_HANDLING to 1. Writing a number into the SharedArrayBuffer will cause the corresponding signal to be raised into the Python thread.
bpo-47186: Replace
JUMP_IF_NOT_EXC_MATCH
byCHECK_EXC_MATCH
+ jump.bpo-47120: Replace the absolute jump opcode
JUMP_NO_INTERRUPT
by the relativeJUMP_BACKWARD_NO_INTERRUPT
.bpo-46841: Avoid unnecessary allocations when comparing code objects.
bpo-47182: Fix a crash when using a named unicode character like
"\N{digit nine}"
after the main interpreter has been initialized a second time.bpo-47162: WebAssembly cannot deal with bad function pointer casts (different count or types of arguments). Python can now use call trampolines to mitigate the problem. Define
PY_CALL_TRAMPOLINE
to enable call trampolines.bpo-46775: Some Windows system error codes(>= 10000) are now mapped into the correct errno and may now raise a subclass of
OSError
. Patch by Dong-hee Na.bpo-47129: Improve error messages in f-string syntax errors concerning empty expressions.
bpo-47117: Fix a crash if we fail to decode characters in interactive mode if the tokenizer buffers are uninitialized. Patch by Pablo Galindo.
bpo-47127: Speed up calls to c functions with keyword arguments by 25% with specialization. Patch by Kumar Aditya.
bpo-47120: Replaced
JUMP_ABSOLUTE
by the relative jumpJUMP_BACKWARD
.bpo-42197:
PyFrame_FastToLocalsWithError()
andPyFrame_LocalsToFast()
are no longer called during profiling nor tracing. C code can access thef_locals
attribute ofPyFrameObject
by callingPyFrame_GetLocals()
.bpo-47070: Improve performance of
array_inplace_repeat
by reducing the number of invocations ofmemcpy
. Refactor therepeat
and inplacerepeat
methods ofarray
,bytes
,bytearray
andunicodeobject
to use the common_PyBytes_Repeat
.bpo-47053: Reduce de-optimization in the specialized
BINARY_OP_INPLACE_ADD_UNICODE
opcode.bpo-47045: Remove the
f_state
field from the _PyInterpreterFrame struct. Add theowner
field to the _PyInterpreterFrame struct to make ownership explicit to simplify clearing and deallocing frames and generators.bpo-46968: Check for the existence of the “sys/auxv.h” header in
faulthandler
to avoid compilation problems in systems where this header doesn’t exist. Patch by Pablo Galindobpo-46329: Use low bit of
LOAD_GLOBAL
to indicate whether to push aNULL
before the global. Helps streamline the call sequence a bit.bpo-46841: Quicken bytecode in-place by storing it as part of the corresponding
PyCodeObject
.bpo-47012: Speed up iteration of
bytes
andbytearray
by 30%. Patch by Kumar Aditya.bpo-47009: Improved the performance of
list.append()
and list comprehensions by optimizing for the common case, where no resize is needed. Patch by Dennis Sweeney.bpo-47005: Improve performance of
bytearray_repeat
andbytearray_irepeat
by reducing the number of invocations ofmemcpy
.bpo-46829: Deprecate passing a message into
asyncio.Future.cancel()
andasyncio.Task.cancel()
bpo-46993: Speed up
bytearray
creation fromlist
andtuple
by 40%. Patch by Kumar Aditya.bpo-39829: Removed the
__len__()
call when initializing a list and moved initializing tolist_extend
. Patch by Jeremiah Pascual.bpo-46944: Speed up throwing exception in generator with
METH_FASTCALL
calling convention. Patch by Kumar Aditya.bpo-46841: Modify
STORE_SUBSCR
to use an inline cache entry (rather than its oparg) as an adaptive counter.bpo-46841: Use inline caching for
PRECALL
andCALL
, and remove the internal machinery for managing the (now unused) non-inline caches.bpo-46881: Statically allocate and initialize the latin1 characters.
bpo-46838: Improve syntax errors for incorrect function definitions. Patch by Pablo Galindo
bpo-43721: Fix docstrings of
getter
,setter
, anddeleter
to clarify that they create a new copy of the property.bpo-43224: Make grammar changes required for PEP 646.
Library¶
bpo-47208: Allow vendors to override
CTYPES_MAX_ARGCOUNT
.bpo-23689:
re
module: fix memory leak when a match is terminated by a signal or memory allocation failure. Patch by Ma Lin.bpo-47167: Allow overriding a future compliance check in
asyncio.Task
.bpo-47151: When subprocess tries to use vfork, it now falls back to fork if vfork returns an error. This allows use in situations where vfork isn’t allowed by the OS kernel.
bpo-47152: Convert the
re
module into a package. Deprecate modulessre_compile
,sre_constants
andsre_parse
.bpo-4833: Add
ZipFile.mkdir()
bpo-27929: Fix
asyncio.loop.sock_connect()
to only resolve names forsocket.AF_INET
orsocket.AF_INET6
families. Resolution may not make sense for other families, likesocket.AF_BLUETOOTH
andsocket.AF_UNIX
.bpo-14265: Adds the fully qualified test name to unittest output
bpo-47061: Deprecate the aifc module.
bpo-39622: Handle Ctrl+C in asyncio programs to interrupt the main task.
bpo-47101:
hashlib.algorithms_available
now lists only algorithms that are provided by activated crypto providers on OpenSSL 3.0. Legacy algorithms are not listed unless the legacy provider has been loaded into the default OSSL context.bpo-47099: All
URLError
exception messages raised inurllib.request.URLopener
now contain a colon betweenftp error
and the rest of the message. Previously,open_ftp()
missed the colon. Patch by Oleg Iarygin.bpo-47099: Exception chaining is changed from
Exception.with_traceback()
/sys.exc_info()
to PEP 3134. Patch by Oleg Iarygin.bpo-47095:
hashlib
’s internal_blake2
module now preferslibb2
from https://www.blake2.net/ over Python’s vendored copy of blake2.bpo-47098: The Keccak Code Package for
hashlib
’s internal_sha3
module has been replaced with tiny_sha3. The module is used as fallback when Python is built without OpenSSL.bpo-47088: Implement
typing.LiteralString
, part of PEP 675. Patch by Jelle Zijlstra.bpo-42885: Optimize
re.search()
,re.split()
,re.findall()
,re.finditer()
andre.sub()
for regular expressions starting with\A
or^
.bpo-23691: Protect the
re.finditer()
iterator from re-entering.bpo-47067: Optimize calling
GenericAlias
objects by using PEP 590vectorcall
and by replacingPyObject_SetAttrString
withPyObject_SetAttr
.bpo-28080: Add the metadata_encoding parameter in the
zipfile.ZipFile
constructor and the--metadata-encoding
option in thezipfile
CLI to allow reading zipfiles using non-standard codecs to encode the filenames within the archive.bpo-47000: Make
io.text_encoding()
returns “utf-8” when UTF-8 mode is enabled.bpo-42369: Fix thread safety of
zipfile._SharedFile.tell()
to avoid a “zipfile.BadZipFile: Bad CRC-32 for file” exception when reading aZipFile
from multiple threads.bpo-38256: Fix
binascii.crc32()
when it is compiled to use zlib’c crc32 to work properly on inputs 4+GiB in length instead of returning the wrong result. The workaround prior to this was to always feed the function data in increments smaller than 4GiB or to just call the zlib module function.We also have
binascii.crc32()
release the GIL when computing on larger inputs aszlib.crc32()
andhashlib
do.This also boosts performance on Windows as it now uses the zlib crc32 implementation for
binascii.crc32()
for a 2-3x speedup.That the stdlib has a crc32 API in two modules is a known historical oddity. This moves us closer to a single implementation behind them.
bpo-47066: Global inline flags (e.g.
(?i)
) can now only be used at the start of the regular expressions. Using them not at the start of expression was deprecated since Python 3.6.bpo-39394: A warning about inline flags not at the start of the regular expression now contains the position of the flag.
bpo-433030: Add support of atomic grouping (
(?>...)
) and possessive quantifiers (*+
,++
,?+
,{m,n}+
) inregular expressions
.bpo-47062: Implement
asyncio.Runner
context manager.bpo-46382:
dataclass()
slots=True
now correctly omits slots already defined in base classes. Patch by Arie Bovenberg.bpo-47057: Use FASTCALL convention for
FutureIter.throw()
bpo-47061: Deprecate the various modules listed by PEP 594:
aifc, asynchat, asyncore, audioop, cgi, cgitb, chunk, crypt, imghdr, msilib, nntplib, nis, ossaudiodev, pipes, smtpd, sndhdr, spwd, sunau, telnetlib, uu, xdrlib
bpo-34790: Remove passing coroutine objects to
asyncio.wait()
.bpo-47039: Normalize
repr()
of asyncio future and task objects.bpo-2604: Fix bug where doctests using globals would fail when run multiple times.
bpo-45150: Add
hashlib.file_digest()
helper for efficient hashing of file object.bpo-34861: Made cumtime the default sorting key for cProfile
bpo-45997: Fix
asyncio.Semaphore
re-aquiring FIFO order.bpo-47022: The
asynchat
,asyncore
andsmtpd
modules have been deprecated since at least Python 3.6. Their documentation and deprecation warnings and have now been updated to note they will removed in Python 3.12 (PEP 594).bpo-43253: Fix a crash when closing transports where the underlying socket handle is already invalid on the Proactor event loop.
bpo-40280:
select.select()
now passesNULL
toselect
for each empty fdset.bpo-47004: Apply bugfixes from importlib_metadata 4.11.3, including bugfix for EntryPoint.extras, which was returning match objects and not the extras strings.
bpo-46998: Allow subclassing of
typing.Any
. Patch by Shantanu Jain.bpo-46995: Deprecate missing
asyncio.Task.set_name()
for third-party task implementations, schedule making it mandatory in Python 3.13.bpo-46994: Accept explicit contextvars.Context in
asyncio.create_task()
andasyncio.loop.create_task()
.bpo-46981:
typing.get_args(typing.Tuple[()])
now returns()
instead of((),)
.bpo-46968: Add
os.sysconf_names['SC_MINSIGSTKSZ']
.bpo-46985: Upgrade pip wheel bundled with ensurepip (pip 22.0.4)
bpo-46968:
faulthandler
: On Linux 5.14 and newer, dynamically determine size of signal handler stack size CPython allocates usinggetauxval(AT_MINSIGSTKSZ)
. This changes allows for Python extension’s request to Linux kernel to use AMX_TILE instruction set on Sapphire Rapids Xeon processor to succeed, unblocking use of the ISA in frameworks.bpo-46917: The
math.nan
value is now always available. Patch by Victor Stinner.bpo-46955: Expose
asyncio.base_events.Server
asasyncio.Server
. Patch by Stefan Zabka.bpo-23325: The
signal
module no longer assumes thatSIG_IGN
andSIG_DFL
are small int singletons.bpo-46932: Update bundled libexpat to 2.4.7
bpo-46933: The
pwd
module is now optional.os.path.expanduser()
returns the path when thepwd
module is not available.bpo-40059: PEP 680, the
tomllib
module. Adds support for parsing TOML.bpo-464471:
asyncio.timeout()
andasyncio.timeout_at()
context managers added. Patch by Tin Tvrtković and Andrew Svetlov.bpo-46805: Added raw datagram socket functions for asyncio:
sock_sendto()
,sock_recvfrom()
andsock_recvfrom_into()
.bpo-46644: No longer require valid typeforms to be callable. This allows
typing.Annotated
to wraptyping.ParamSpecArgs
anddataclasses.InitVar
. Patch by Gregory Beauregard.bpo-46581: Brings
ParamSpec
propagation forGenericAlias
in line withConcatenate
(and others).bpo-45413: Define posix_venv and nt_venv sysconfig installation schemes to be used for bootstrapping new virtual environments. Add venv sysconfig installation scheme to get the appropriate one of the above. The schemes are identical to the pre-existing posix_prefix and nt install schemes. The
venv
module now uses the venv scheme to create new virtual environments instead of hardcoding the paths depending only on the platform. Downstream Python distributors customizing the posix_prefix or nt install scheme in a way that is not compatible with the install scheme used in virtual environments are encouraged not to customize the venv schemes. When Python itself runs in a virtual environment,sysconfig.get_default_scheme()
andsysconfig.get_preferred_scheme()
withkey="prefix"
returns venv.bpo-43224: Implement support for PEP 646 in typing.py.
bpo-43224: Allow unpacking types.GenericAlias objects, e.g.
*tuple[int, str]
.bpo-46557: Warnings captured by the logging module are now logged without a format string to prevent systems that group logs by the msg argument from grouping captured warnings together.
bpo-41370:
typing.get_type_hints()
now supports evaluating strings as forward references in PEP 585 generic aliases.bpo-46607: Add
DeprecationWarning
toLegacyInterpolation
, deprecated in the docstring since Python 3.2. Will be removed in Python 3.13. UseBasicInterpolation
orExtendedInterpolation
instead.bpo-26120:
pydoc
now excludes __future__ imports from the module’s data items.bpo-46480: Add
typing.assert_type()
. Patch by Jelle Zijlstra.bpo-46421: Fix a unittest issue where if the command was invoked as
python -m unittest
and the filename(s) began with a dot (.), aValueError
is returned.bpo-46245: Add optional parameter dir_fd in
shutil.rmtree()
.bpo-22859:
usageExit()
is marked deprecated, to be removed in 3.13.bpo-46170: Improve the error message when you try to subclass an instance of
typing.NewType
.bpo-20392: Fix inconsistency with uppercase file extensions in
MimeTypes.guess_type()
. Patch by Kumar Aditya.bpo-46030: Add
LOCAL_CREDS
,LOCAL_CREDS_PERSISTENT
andSCM_CREDS2
FreeBSD constants to the socket module.bpo-44439: Fix
.write()
method of a member file inZipFile
, when the input data is an object that supports the buffer protocol, the file length may be wrong.bpo-45171: Fix handling of the
stacklevel
argument to logging functions in thelogging
module so that it is consistent accross all logging functions and, as advertised, similar to thestacklevel
argument used inwarn()
.bpo-24959: Fix bug where
unittest
sometimes drops frames from tracebacks of exceptions raised in tests.bpo-44859: Raise more accurate and PEP 249 compatible exceptions in
sqlite3
.Raise
InterfaceError
instead ofProgrammingError
forSQLITE_MISUSE
errors.Don’t overwrite
BufferError
withValueError
when conversion to BLOB fails.Raise
ProgrammingError
instead ofWarning
if user tries toexecute()
more than one SQL statement.Raise
ProgrammingError
instead ofValueError
if an SQL query contains null characters.
bpo-44493: Add missing terminated NUL in sockaddr_un’s length
This was potentially observable when using non-abstract AF_UNIX datagram sockets to processes written in another programming language.
bpo-41930: Add
serialize()
anddeserialize()
support tosqlite3
. Patch by Erlend E. Aasland.bpo-33178: Added
ctypes.BigEndianUnion
andctypes.LittleEndianUnion
classes, as originally documented in the library docs but not yet implemented.bpo-43352: Add an Barrier object in synchronization primitives of asyncio Lib in order to be consistant with Barrier from threading and multiprocessing libs*
bpo-35859:
re
module, fix a few bugs about capturing group. In rare cases, capturing group gets an incorrect string. Patch by Ma Lin.
Documentation¶
bpo-47040: Clarified the old Python versions compatiblity note of
binascii.crc32()
/zlib.adler32()
/zlib.crc32()
functions.bpo-46033: Clarify
for
statement execution in its doc.bpo-45790: Adjust inaccurate phrasing in Defining Extension Types: Tutorial about the
ob_base
field and the macros used to access its contents.bpo-42340: Document that in some circumstances
KeyboardInterrupt
may cause the code to enter an inconsistent state. Provided a sample workaround to avoid it if needed.bpo-41233: Link the errnos referenced in
Doc/library/exceptions.rst
to their respective section inDoc/library/errno.rst
, and vice versa. Previously this was only done for EINTR and InterruptedError. Patch by Yan “yyyyyyyan” Orestes.
Tests¶
bpo-47205: Skip test for
sched_getaffinity()
andsched_setaffinity()
error case on FreeBSD.bpo-46126: Restore ‘descriptions’ when running tests internally.
bpo-47104: Rewrite
asyncio.to_thread()
tests to useunittest.IsolatedAsyncioTestCase
.bpo-40280: The test suite is now passing on the Emscripten platform. All fork, socket, and subprocess-based tests are skipped.
bpo-47037: Skip
strftime("%4Y")
feature test on Windows. It can cause an assertion error in debug builds.bpo-46587: Skip tests if platform’s
strftime
does not support non-portable glibc extensions.bpo-47015: A test case for
os.sendfile()
is converted from deprecatedasyncore
(see PEP 594) toasyncio
. Patch by Oleg Iarygin.
Build¶
bpo-40280: Add configure option
--enable-wasm-dynamic-linking
to enabledlopen
and MAIN_MODULE / SIDE_MODULE onwasm32-emscripten
.bpo-46023:
makesetup
now detects and skips all duplicated module definitions. The first entry wins.bpo-40280: Add SOABI
wasm32-emscripten
for Emscripten andwasm32-wasi
for WASI on 32bit WASM as well aswasm64
counter parts.bpo-47032: Ensure Windows install builds fail correctly with a non-zero exit code when part of the build fails.
bpo-47024: Update OpenSSL to 1.1.1n for macOS installers and all Windows builds.
bpo-46996: The
tkinter
package now requires Tcl/Tk version 8.5.12 or newer.bpo-46973: Add
regen-configure
make target to regenerate configure script with Christian’s container imagequay.io/tiran/cpython_autoconf:269
.bpo-46917: Building Python now requires support of IEEE 754 floating point numbers. Patch by Victor Stinner.
bpo-45774:
configure
now verifies that all SQLite C APIs needed for thesqlite3
extension module are found.
Windows¶
bpo-47194: Update
zlib
to v1.2.12 to resolve CVE-2018-25032.bpo-47171: Enables installing the
py.exe
launcher on Windows ARM64.bpo-46566: Upgraded Python Launcher for Windows to support a new
-V:company/tag
argument for full PEP 514 support and to detect ARM64 installs. The-64
suffix on arguments is deprecated, but still selects any non-32-bit install. SettingPYLAUNCHER_ALLOW_INSTALL
and specifying a version that is not installed will attempt to install the requested version from the Microsoft Store.bpo-47086: The installer for Windows now includes documentation as loose HTML files rather than a single compiled
.chm
file.bpo-46907: Update Windows installer to use SQLite 3.38.1.
bpo-44549: Update bzip2 to 1.0.8 in Windows builds to mitigate CVE-2016-3189 and CVE-2019-12900
bpo-46948: Prevent CVE-2022-26488 by ensuring the Add to PATH option in the Windows installer uses the correct path when being repaired.
macOS¶
Tools/Demos¶
bpo-40280: Replace Emscripten’s limited shell with Katie Bell’s browser-ui REPL from python-wasm project.
C API¶
bpo-40421: Add
PyFrame_GetBuiltins
,PyFrame_GetGenerator
andPyFrame_GetGlobals
C-API functions to access frame object attributes safely from C code.bpo-46850: Move the private
_PyFrameEvalFunction
type, and private_PyInterpreterState_GetEvalFrameFunc()
and_PyInterpreterState_SetEvalFrameFunc()
functions to the internal C API. The_PyFrameEvalFunction
callback function type now uses the_PyInterpreterFrame
type which is part of the internal C API. Patch by Victor Stinner.bpo-46850: Move the private undocumented
_PyEval_EvalFrameDefault()
function to the internal C API. The function now uses the_PyInterpreterFrame
type which is part of the internal C API. Patch by Victor Stinner.bpo-46850: Remove the private undocumented function
_PyEval_CallTracing()
from the C API. Call the publicsys.call_tracing()
function instead. Patch by Victor Stinner.bpo-46850: Remove the private undocumented function
_PyEval_GetCoroutineOriginTrackingDepth()
from the C API. Call the publicsys.get_coroutine_origin_tracking_depth()
function instead. Patch by Victor Stinner.bpo-46850: Remove the following private undocumented functions from the C API:
_PyEval_GetAsyncGenFirstiter()
_PyEval_GetAsyncGenFinalizer()
_PyEval_SetAsyncGenFirstiter()
_PyEval_SetAsyncGenFinalizer()
Call the public
sys.get_asyncgen_hooks()
andsys.set_asyncgen_hooks()
functions instead. Patch by Victor Stinner.bpo-46987: Remove private functions
_PySys_GetObjectId()
and_PySys_SetObjectId()
. Patch by Dong-hee Na.bpo-46906: Add new functions to pack and unpack C double (serialize and deserialize):
PyFloat_Pack2()
,PyFloat_Pack4()
,PyFloat_Pack8()
,PyFloat_Unpack2()
,PyFloat_Unpack4()
andPyFloat_Unpack8()
. Patch by Victor Stinner.
Python 3.11.0 alpha 6¶
Release date: 2022-03-07
Core and Builtins¶
bpo-46940: Avoid overriding
AttributeError
metadata information for nested attribute access calls. Patch by Pablo Galindo.bpo-46927: Include the type’s name in the error message for subscripting non-generic types.
bpo-46921: Support vectorcall for
super()
. Patch by Ken Jin.bpo-46841: Fix incorrect handling of inline cache entries when specializing
BINARY_OP
.bpo-46841: Use an oparg to simplify the construction of helpful error messages in
GET_AWAITABLE
.bpo-46903: Make sure that str subclasses can be used as attribute names for instances with virtual dictionaries. Fixes regression in 3.11alpha
bpo-46841: Add more detailed specialization failure stats for
COMPARE_OP
followed byEXTENDED_ARG
.bpo-46891: Fix bug introduced during 3.11alpha where subclasses of
types.ModuleType
with__slots__
were not initialized correctly, resulting in an interpreter crash.bpo-46841: Use inline caching for
LOAD_ATTR
,LOAD_METHOD
, andSTORE_ATTR
.bpo-46841: Use inline cache for
BINARY_SUBSCR
.bpo-46841: Use inline caching for
COMPARE_OP
.bpo-46864: Deprecate
PyBytesObject.ob_shash
. It will be removed in Python 3.13.bpo-46841: Use inline caching for
UNPACK_SEQUENCE
.bpo-46845: Reduces dict size by removing hash value from hash table when all inserted keys are Unicode. For example,
sys.getsizeof(dict.fromkeys("abcdefg"))
becomes 272 bytes from 352 bytes on 64bit platform.bpo-46841: Use inline cache for
LOAD_GLOBAL
.bpo-46852: Rename the private undocumented
float.__set_format__()
method tofloat.__setformat__()
to fix a typo introduced in Python 3.7. The method is only used by test_float. Patch by Victor Stinner.bpo-46852: Remove the undocumented private
float.__set_format__()
method, previously known asfloat.__setformat__()
in Python 3.7. Its docstring said: “You probably don’t want to use this function. It exists mainly to be used in Python’s test suite.” Patch by Victor Stinner.bpo-40116: Fix regression that dict.update(other) may don’t respect iterate order of other when other is key sharing dict.
bpo-46712: Share global string identifiers in deep-frozen modules.
bpo-46430: Fix memory leak in interned strings of deep-frozen modules.
bpo-46841: Store
BINARY_OP
caches inline using a newCACHE
instruction.bpo-45107: Specialize
LOAD_METHOD
for instances with a dict.bpo-44337: Reduce the memory usage of specialized
LOAD_ATTR
andSTORE_ATTR
instructions.bpo-46729: Add number of sub-exceptions to
BaseException.__str__()
.bpo-45885: Don’t un-adapt
COMPARE_OP
when collecting specialization stats.bpo-46329: Fix specialization stats gathering for
PRECALL
instructions.bpo-46794: Bump up the libexpat version into 2.4.6
bpo-46823: Implement a specialized combined opcode
LOAD_FAST__LOAD_ATTR_INSTANCE_VALUE
. Patch by Dennis Sweeney.bpo-46820: Fix parsing a numeric literal immediately (without spaces) followed by “not in” keywords, like in
1not in x
. Now the parser only emits a warning, not a syntax error.bpo-46329: Move
KW_NAMES
beforePRECALL
instruction in call sequence. Changeoperand
ofCALL
to matchPRECALL
for easier specialization.bpo-46808: Remove the
NEXT_BLOCK
macro from compile.c, and make the compiler automatically generate implicit blocks when they are needed.bpo-46329: Add
PUSH_NULL
instruction. This is used as a prefix when evaluating a callable, so that the stack has the same shape for methods and other calls.PRECALL_FUNCTION
andPRECALL_METHOD
are merged into a singlePRECALL
instruction.There is no change in semantics.
bpo-46762: Fix an assert failure in debug builds when a ‘<’, ‘>’, or ‘=’ is the last character in an f-string that’s missing a closing right brace.
bpo-46730: Message of AttributeError caused by getting, setting or deleting a property without the corresponding function now mentions that the attribute is in fact a property and also specifies type of the class that it belongs to.
bpo-46724: Make sure that all backwards jumps use the
JUMP_ABSOLUTE
instruction, rather thanJUMP_FORWARD
with an argument of(2**32)+offset
.bpo-46732: Correct the docstring for the
__bool__()
method. Patch by Jelle Zijlstra.bpo-46072: Add more detailed specialization failure statistics for
BINARY_OP
.bpo-46707: Avoid potential exponential backtracking when producing some syntax errors involving lots of brackets. Patch by Pablo Galindo.
bpo-46323:
ctypes
now allocates memory on the stack instead of on the heap to pass arguments while calling a Python callback function. Patch by Dong-hee Na.bpo-45923: Add a quickened form of
RESUME
that skips quickening checks.bpo-46702: Specialize
UNPACK_SEQUENCE
fortuple
andlist
unpackings.bpo-46072: Opcode pair stats are now gathered with
--enable-pystats
. DefiningDYNAMIC_EXECUTION_PROFILE
orDXPAIRS
no longer has any effect.bpo-46675: Allow more than 16 items in a split dict before it is combined. The limit is now 254.
bpo-40479: Add a missing call to
va_end()
inModules/_hashopenssl.c
.bpo-46323: Use
PyObject_Vectorcall()
while calling ctypes callback function. Patch by Dong-hee Na.bpo-46615: When iterating over sets internally in
setobject.c
, acquire strong references to the resulting items from the set. This prevents crashes in corner-cases of various set operations where the set gets mutated.bpo-45828: The bytecode compiler now attempts to apply runtime stack manipulations at compile-time (whenever it is feasible to do so).
bpo-30496: Fixed a minor portability issue in the implementation of
PyLong_FromLong()
, and added a fast path for single-digit integers toPyLong_FromLongLong()
.
Library¶
bpo-25707: Fixed a file leak in
xml.etree.ElementTree.iterparse()
when the iterator is not exhausted. Patch by Jacob Walls.bpo-46877: Export
unittest.doModuleCleanups()
inunittest
. Patch by Kumar Aditya.bpo-46848: For performance, use the optimized string-searching implementations from
find()
andrfind()
forfind()
andrfind()
.bpo-46736:
SimpleHTTPRequestHandler
now uses HTML5 grammar. Patch by Dong-hee Na.bpo-44886: Inherit asyncio proactor datagram transport from
asyncio.DatagramTransport
.bpo-46827: Support UDP sockets in
asyncio.loop.sock_connect()
for selector-based event loops. Patch by Thomas Grainger.bpo-46811: Make test suite support Expat >=2.4.5
bpo-46252: Raise
TypeError
ifssl.SSLSocket
is passed to transport-based APIs.bpo-46784: Fix libexpat symbols collisions with user dynamically loaded or statically linked libexpat in embedded Python.
bpo-46786: The HTML serialisation in xml.etree.ElementTree now writes
embed
,source
,track
andwbr
as empty tags, as defined in HTML 5.bpo-39327:
shutil.rmtree()
can now work with VirtualBox shared folders when running from the guest operating-system.bpo-45390: Propagate
asyncio.CancelledError
message from inner task to outer awaiter.bpo-46756: Fix a bug in
urllib.request.HTTPPasswordMgr.find_user_password()
andurllib.request.HTTPPasswordMgrWithPriorAuth.is_authenticated()
which allowed to bypass authorization. For example, access to URIexample.org/foobar
was allowed if the user was authorized for URIexample.org/foo
.bpo-46737:
random.gauss()
andrandom.normalvariate()
now have default arguments.bpo-46752: Add task groups to asyncio (structured concurrency, inspired by Trio’s nurseries). This also introduces a change to task cancellation, where a cancelled task can’t be cancelled again until it calls .uncancel().
bpo-46333: The
__repr__()
method oftyping.ForwardRef
now includes themodule
parameter oftyping.ForwardRef
when it is set.bpo-46643: In
typing.get_type_hints()
, support evaluating stringifiedParamSpecArgs
andParamSpecKwargs
annotations. Patch by Gregory Beauregard.bpo-45863: When the
tarfile
module creates a pax format archive, it will put an integer representation of timestamps in the ustar header (if possible) for the benefit of older unarchivers, in addition to the existing full-precision timestamps in the pax extended header.bpo-46066: Deprecate kwargs-based syntax for
typing.TypedDict
definitions. It had confusing semantics when specifying totality, and was largely unused. Patch by Jingchen Ye.bpo-46676: Make
typing.ParamSpec
args and kwargs equal to themselves. Patch by Gregory Beauregard.bpo-46323:
ctypes.CFUNCTYPE()
andctypes.WINFUNCTYPE()
now fail to create the type if its_argtypes_
member contains too many arguments. Previously, the error was only raised when calling a function. Patch by Victor Stinner.bpo-46672: Fix
NameError
inasyncio.gather()
when initial type check fails.bpo-46659: The
calendar.LocaleTextCalendar
andcalendar.LocaleHTMLCalendar
classes now uselocale.getlocale()
, instead of usinglocale.getdefaultlocale()
, if no locale is specified. Patch by Victor Stinner.bpo-46659: The
locale.getdefaultlocale()
function is deprecated and will be removed in Python 3.13. Uselocale.setlocale()
,locale.getpreferredencoding(False)
andlocale.getlocale()
functions instead. Patch by Victor Stinner.bpo-46655: In
typing.get_type_hints()
, support evaluating bare stringifiedTypeAlias
annotations. Patch by Gregory Beauregard.bpo-45948: Fixed a discrepancy in the C implementation of the
xml.etree.ElementTree
module. Now, instantiating anxml.etree.ElementTree.XMLParser
with atarget=None
keyword provides a defaultxml.etree.ElementTree.TreeBuilder
target as the Python implementation does.bpo-46626: Expose Linux’s
IP_BIND_ADDRESS_NO_PORT
option insocket
.bpo-46521: Fix a bug in the
codeop
module that was incorrectly identifying invalid code involving string quotes as valid code.bpo-46571: Improve
typing.no_type_check()
.Now it does not modify external classes and functions. We also now correctly mark classmethods as not to be type checked.
bpo-46400: expat: Update libexpat from 2.4.1 to 2.4.4
bpo-46556: Deprecate undocumented support for using a
pathlib.Path
object as a context manager.bpo-46534: Implement PEP 673
typing.Self
. Patch by James Hilton-Balfe.bpo-46522: Make various module
__getattr__
AttributeErrors more closely match a typical AttributeErrorbpo-46475: Add
typing.Never
andtyping.assert_never()
. Patch by Jelle Zijlstra.bpo-46333: The
__eq__()
and__hash__()
methods oftyping.ForwardRef
now honor themodule
parameter oftyping.ForwardRef
. Forward references from different modules are now differentiated.bpo-46246: Add missing
__slots__
toimportlib.metadata.DeprecatedList
. Patch by Arie Bovenberg.bpo-46232: The
ssl
module now handles certificates with bit strings in DN correctly.bpo-46195:
typing.get_type_hints()
no longer addsOptional
to parameters withNone
as a default. This aligns to changes to PEP 484 in https://github.com/python/peps/pull/689bpo-31369: Add
RegexFlag
tore.__all__
and documented it. AddNOFLAG
to indicate no flags being set.bpo-45898:
ctypes
no longer definesffi_type_*
symbols incfield.c
. The symbols have been provided by libffi for over a decade.bpo-44953: Calling
operator.itemgetter
objects andoperator.attrgetter
objects is now faster due to use of the vectorcall calling convention.bpo-44289: Fix an issue with
is_tarfile()
method when using fileobj argument: position in the fileobj was advanced forward which made it unreadable withtarfile.TarFile.open()
.bpo-44011: Reimplement SSL/TLS support in asyncio, borrow the implementation from uvloop library.
bpo-41086: Make the
configparser.ConfigParser
constructor raiseTypeError
if theinterpolation
parameter is not of typeconfigparser.Interpolation
bpo-29418: Implement
inspect.ismethodwrapper()
and fixinspect.isroutine()
for cases where methodwrapper is given. Patch by Hakan Çelik.bpo-14156: argparse.FileType now supports an argument of ‘-’ in binary mode, returning the .buffer attribute of sys.stdin/sys.stdout as appropriate. Modes including ‘x’ and ‘a’ are treated equivalently to ‘w’ when argument is ‘-’. Patch contributed by Josh Rosenberg
Documentation¶
bpo-42238:
Doc/tools/rstlint.py
has moved to its own repository and is now packaged on PyPI assphinx-lint
.
Tests¶
bpo-46913: Fix test_faulthandler.test_sigfpe() if Python is built with undefined behavior sanitizer (UBSAN): disable UBSAN on the faulthandler_sigfpe() function. Patch by Victor Stinner.
bpo-46760: Remove bytecode offsets from expected values in test.test_dis module. Reduces the obstacles to modifying the VM or compiler.
bpo-46708: Prevent default asyncio event loop policy modification warning after
test_asyncio
execution.bpo-46678: The function
make_legacy_pyc
inLib/test/support/import_helper.py
no longer fails whenPYTHONPYCACHEPREFIX
is set to a directory on a different device from where tempfiles are stored.bpo-46623: Skip test_pair() and test_speech128() of test_zlib on s390x since they fail if zlib uses the s390x hardware accelerator. Patch by Victor Stinner.
Build¶
bpo-46860: Respect
--with-suffix
when building on case-insensitive file systems.bpo-46656: Building Python now requires a C11 compiler without optional C11 features. Patch by Victor Stinner.
bpo-46656: Building Python now requires support for floating point Not-a-Number (NaN): remove the
Py_NO_NAN
macro. Patch by by Victor Stinner.bpo-46640: Building Python now requires a C99
<math.h>
header file providing aNAN
constant, or the__builtin_nan()
built-in function. Patch by Victor Stinner.bpo-46608: Exclude marshalled-frozen data if deep-freezing to save 300 KB disk space. This includes adding a new
is_package
field to_frozen
. Patch by Kumar Aditya.bpo-40280: Fix wasm32-emscripten test failures and platform issues. - Disable syscalls that are not supported or don’t work, e.g. wait, getrusage, prlimit, mkfifo, mknod, setres[gu]id, setgroups. - Use fd_count to cound open fds. - Add more checks for subprocess and fork. - Add workarounds for missing _multiprocessing and failing socket.accept(). - Enable bzip2. - Disable large file support. - Disable signal.alarm.
bpo-46430: Intern strings in deep-frozen modules. Patch by Kumar Aditya.
Windows¶
bpo-46744: The default all users install directory for ARM64 is now under the native
Program Files
folder, rather thanProgram Files (Arm)
which is intended for ARM (32-bit) files.bpo-46567: Adds Tcl and Tk support for Windows ARM64. This also adds IDLE to the installation.
bpo-46638: Ensures registry virtualization is consistently disabled. For 3.10 and earlier, it remains enabled (some registry writes are protected), while for 3.11 and later it is disabled (registry modifications affect all applications).
IDLE¶
C API¶
bpo-46748: Python’s public headers no longer import
<stdbool.h>
, leaving code that embedd/extends Python free to definebool
,true
andfalse
.bpo-46836: Move the
PyFrameObject
type definition (struct _frame
) to the internal C APIpycore_frame.h
header file. Patch by Victor Stinner.bpo-45459: Rename
Include/buffer.h
header file toInclude/pybuffer.h
to avoid conflits with projects having an existingbuffer.h
header file. Patch by Victor Stinner.bpo-45412: Remove the
HAVE_PY_SET_53BIT_PRECISION
macro (moved to the internal C API). Patch by Victor Stinner.bpo-46613: Added function
PyType_GetModuleByDef()
, which allows accesss to module state when a method’s defining class is not available.
Python 3.11.0 alpha 5¶
Release date: 2022-02-03
Core and Builtins¶
bpo-45773: Remove two invalid “peephole” optimizations from the bytecode compiler.
bpo-46564: Do not create frame objects when creating
super
object. Patch by Kumar Aditya.bpo-45885: Added more fined-grained specialization failure stats regarding the
COMPARE_OP
bytecode.bpo-44977: The delegation of
int()
to__trunc__()
is now deprecated. Callingint(a)
whentype(a)
implements__trunc__()
but not__int__()
or__index__()
now raises aDeprecationWarning
.bpo-46458: Reorder code emitted by the compiler for a
try
-except
block so that theelse
block’s code immediately follows thetry
body (without a jump). This is more optimal for the happy path.bpo-46527: Allow passing
iterable
as a keyword argument toenumerate()
again. Patch by Jelle Zijlstra.bpo-46528: Replace several stack manipulation instructions (
DUP_TOP
,DUP_TOP_TWO
,ROT_TWO
,ROT_THREE
,ROT_FOUR
, andROT_N
) with newCOPY
andSWAP
instructions.bpo-46329: Use two or three bytecodes to implement most calls.
Calls without named arguments are implemented as a sequence of two instructions:
PRECALL; CALL
. Calls with named arguments are implemented as a sequence of three instructions:PRECALL; KW_NAMES; CALL
. There are two differentPRECALL
instructions:PRECALL_FUNTION
andPRECALL_METHOD
. The latter pairs withLOAD_METHOD
.This partition into pre-call and call allows better specialization, and thus better performance ultimately.
There is no change in semantics.
bpo-46503: Fix an assert when parsing some invalid N escape sequences in f-strings.
bpo-46431: Improve error message on invalid calls to
BaseExceptionGroup.__new__()
.bpo-46476: Fix memory leak in code objects generated by deepfreeze. Patch by Kumar Aditya.
bpo-46481: Speed up calls to
weakref.ref.__call__()
by using the PEP 590vectorcall
calling convention. Patch by Dong-hee Na.bpo-46417: Fix a race condition on setting a type
__bases__
attribute: the internal functionadd_subclass()
now gets thePyTypeObject.tp_subclasses
member after callingPyWeakref_NewRef()
which can trigger a garbage collection which can indirectly modifyPyTypeObject.tp_subclasses
. Patch by Victor Stinner.bpo-46417:
python -X showrefcount
now shows the total reference count after clearing and destroyed the main Python interpreter. Previously, it was shown before. Patch by Victor Stinner.bpo-43683: Add ASYNC_GEN_WRAP opcode to wrap the value to be yielded in async generators. Removes the need to special case async generators in the
YIELD_VALUE
instruction.bpo-46407: Optimize some modulo operations in
Objects/longobject.c
. Patch by Jeremiah Vivian.bpo-46409: Add new
RETURN_GENERATOR
bytecode to make generators. Simplifies calling Python functions in the VM, as they no longer any need to special case generator functions.Also add
JUMP_NO_INTERRUPT
bytecode that acts likeJUMP_ABSOLUTE
, but does not check for interrupts.bpo-46406: The integer division
//
implementation has been optimized to better let the compiler understand its constraints. It can be 20% faster on the amd64 platform when dividing an int by a value smaller than2**30
.bpo-46383: Fix invalid signature of
_zoneinfo
’smodule_free
function to resolve a crash on wasm32-emscripten platform.bpo-46361: Ensure that “small” integers created by
int.from_bytes()
anddecimal.Decimal
are properly cached.bpo-46161: Fix the class building error when the arguments are constants and CALL_FUNCTION_EX is used.
bpo-46028: Fixes calculation of
sys._base_executable
when inside a virtual environment that uses symlinks with different binary names than the base environment provides.bpo-46091: Correctly calculate indentation levels for lines with whitespace character that are ended by line continuation characters. Patch by Pablo Galindo
bpo-30512: Add CAN Socket support for NetBSD.
bpo-46045: Do not use POSIX semaphores on NetBSD
bpo-44024: Improve the exc:
TypeError
message for non-string second arguments passed to the built-in functionsgetattr()
andhasattr()
. Patch by Géry Ogam.
Library¶
bpo-46624: Restore support for non-integer arguments of
random.randrange()
andrandom.randint()
.bpo-46591: Make the IDLE doc URL on the About IDLE dialog clickable.
bpo-46565: Remove loop variables that are leaking into modules’ namespaces.
bpo-46553: In
typing.get_type_hints()
, support evaluating bare stringifiedClassVar
annotations. Patch by Gregory Beauregard.bpo-46544: Don’t leak
x
&uspace
intermediate vars intextwrap.TextWrapper
.bpo-46487: Add the
get_write_buffer_limits
method toasyncio.transports.WriteTransport
and to the SSL transport.bpo-45173: Note the configparser deprecations will be removed in Python 3.12.
bpo-45162: The deprecated
unittest
APIs removed in 3.11a1 have been temporarily restored to be removed in 3.12 while cleanups in external projects go in.bpo-46539: In
typing.get_type_hints()
, support evaluating stringifiedClassVar
andFinal
annotations insideAnnotated
. Patch by Gregory Beauregard.bpo-46510: Add missing test for
types.TracebackType
andtypes.FrameType
. Calculate them directly from the caught exception without callingsys.exc_info()
.bpo-46491: Allow
typing.Annotated
to wraptyping.Final
andtyping.ClassVar
. Patch by Gregory Beauregard.bpo-46483: Remove
__class_getitem__()
frompathlib.PurePath
as this class was not supposed to be generic.bpo-46436: Fix command-line option
-d
/--directory
in modulehttp.server
which is ignored when combined with command-line option--cgi
. Patch by Géry Ogam.bpo-41403: Make
mock.patch()
raise aTypeError
with a relevant error message on invalid arg. Previously it allowed a crypticAttributeError
to escape.bpo-46474: In
importlib.metadata.EntryPoint.pattern
, avoid potential REDoS by limiting ambiguity in consecutive whitespace.bpo-46474: Removed private method from
importlib.metadata.Path
. Sync with importlib_metadata 4.10.0.bpo-46470: Remove unused branch from
typing._remove_dups_flatten
bpo-46469:
asyncio
generic classes now returntypes.GenericAlias
in__class_getitem__
instead of the same class.bpo-41906: Support passing filter instances in the
filters
values ofhandlers
andloggers
in the dictionary passed tologging.config.dictConfig()
.bpo-46422: Use
dis.Positions
indis.Instruction
instead of a regulartuple
.bpo-46434:
pdb
now gracefully handleshelp
when__doc__
is missing, for example when run with pregenerated optimized.pyc
files.bpo-43869: Python uses the same time Epoch on all platforms. Add an explicit unit test to ensure that it’s the case. Patch by Victor Stinner.
bpo-46414: Add
typing.reveal_type()
. Patch by Jelle Zijlstra.bpo-40280:
subprocess
now imports Windows-specific imports whenmsvcrt
module is available, and POSIX-specific imports on all other platforms. This gives a clean exception when_posixsubprocess
is not available (e.g. Emscripten browser target).bpo-40066:
IntEnum
,IntFlag
, andStrEnum
use the mixed-in type for theirstr()
andformat()
output.bpo-46316: Optimize
pathlib.Path.iterdir()
by removing an unnecessary check for special entries.bpo-29688: Document
pathlib.Path.absolute()
(which has always existed).bpo-43012: The pathlib module’s obsolete and internal
_Accessor
class has been removed to prepare the terrain for upcoming enhancements to the module.bpo-46258: Speed up
math.isqrt()
for small positive integers by replacing two division steps with a lookup table.bpo-46242: Improve error message when creating a new
enum.Enum
type subclassing an existingEnum
with_member_names_
usingenum.Enum.__call__()
.bpo-43118: Fix a bug in
inspect.signature()
that was causing it to fail on some subclasses of classes with a__text_signature__
referencing module globals. Patch by Weipeng Hong.bpo-26552: Fixed case where failing
asyncio.ensure_future()
did not close the coroutine. Patch by Kumar Aditya.bpo-21987: Fix an issue with
tarfile.TarFile.getmember()
getting a directory name with a trailing slash.bpo-46124: Update
zoneinfo
to rely on importlib.resources traversable API.bpo-46103: Now
inspect.getmembers()
only gets__bases__
attribute from class type. Patch by Weipeng Hong.bpo-46080: Fix exception in argparse help text generation if a
argparse.BooleanOptionalAction
argument’s default isargparse.SUPPRESS
and it hashelp
specified. Patch by Felix Fontein.bpo-44791: Fix substitution of
ParamSpec
inConcatenate
with different parameter expressions. Substitution with a list of types returns now a tuple of types. Substitution withConcatenate
returns now aConcatenate
with concatenated lists of arguments.
Documentation¶
bpo-46463: Fixes
escape4chm.py
script used when building the CHM documentation file
Tests¶
bpo-43478: Mocks can no longer be provided as the specs for other Mocks. As a result, an already-mocked object cannot be passed to
mock.Mock()
. This can uncover bugs in tests since these Mock-derived Mocks will always pass certain tests (e.g. isinstance) and builtin assert functions (e.g. assert_called_once_with) will unconditionally pass.bpo-46616: Ensures
test_importlib.test_windows
cleans up registry keys after completion.bpo-44359: test_ftplib now silently ignores socket errors to prevent logging unhandled threading exceptions. Patch by Victor Stinner.
bpo-46600: Fix test_gdb.test_pycfunction() for Python built with
clang -Og
. Tolerate inlined functions in the gdb traceback. Patch by Victor Stinner.bpo-46542: Fix a Python crash in test_lib2to3 when using Python built in debug mode: limit the recursion limit. Patch by Victor Stinner.
bpo-46576: test_peg_generator now disables compiler optimization when testing compilation of its own C extensions to significantly speed up the testing on non-debug builds of CPython.
bpo-46542: Fix
test_json
tests checking forRecursionError
: modify these tests to usesupport.infinite_recursion()
. Patch by Victor Stinner.bpo-13886: Skip test_builtin PTY tests on non-ASCII characters if the readline module is loaded. The readline module changes input() behavior, but test_builtin is not intented to test the readline module. Patch by Victor Stinner.
bpo-40280: Add
test.support.requires_fork()
decorators to mark tests that require a workingos.fork()
.bpo-40280: Add
test.support.requires_subprocess()
decorator to mark tests which require workingsubprocess
module oros.spawn*
. The wasm32-emscripten platform has no support for processes.bpo-46126: Disable ‘descriptions’ when running tests internally.
Build¶
bpo-46602: Tidied up configure.ac so that conftest.c is truncated rather than appended. This assists in the case where the ‘rm’ of conftest.c fails to happen between tests. Downstream issues such as a clobbered SOABI can result.
bpo-46600: Fix the test checking if the C compiler supports
-Og
option in the./configure
script to also use-Og
on clang which supports it. Patch by Victor Stinner.bpo-38472: Fix GCC detection in setup.py when cross-compiling. The C compiler is now run with LC_ALL=C. Previously, the detection failed with a German locale.
bpo-46513: configure no longer uses
AC_C_CHAR_UNSIGNED
macro andpyconfig.h
no longer defines reserved symbol__CHAR_UNSIGNED__
.bpo-46471: Use global singletons for single byte bytes objects in deepfreeze.
bpo-46443: Deepfreeze now uses cached small integers as it saves some space for common small integers.
bpo-46429: Merge all deep-frozen files into one for space savings. Patch by Kumar Aditya.
bpo-45569: The build now defaults to using 30-bit digits for Python integers. Previously either 15-bit or 30-bit digits would be selected, depending on the platform. 15-bit digits may still be selected using the
--enable-big-digits=15
option to theconfigure
script, or by definingPYLONG_BITS_IN_DIGIT
inpyconfig.h
.bpo-45925: Update Windows installer to use SQLite 3.37.2.
bpo-43112: Detect musl libc as a separate SOABI (tagged as
linux-musl
).
Windows¶
bpo-33125: The traditional EXE/MSI based installer for Windows is now available for ARM64
bpo-46362: os.path.abspath(“C:CON”) is now fixed to return “\.CON”, not the same path. The regression was true of all legacy DOS devices such as COM1, LPT1, or NUL.
bpo-44934: The installer now offers a command-line only option to add the installation directory to the end of
PATH
instead of at the start.
macOS¶
bpo-45925: Update macOS installer to SQLite 3.37.2.
IDLE¶
bpo-45296: Clarify close, quit, and exit in IDLE. In the File menu, ‘Close’ and ‘Exit’ are now ‘Close Window’ (the current one) and ‘Exit’ is now ‘Exit IDLE’ (by closing all windows). In Shell, ‘quit()’ and ‘exit()’ mean ‘close Shell’. If there are no other windows, this also exits IDLE.
C API¶
bpo-40170: Remove the
PyHeapType_GET_MEMBERS()
macro. It was exposed in the public C API by mistake, it must only be used by Python internally. Use thePyTypeObject.tp_members
member instead. Patch by Victor Stinner.bpo-40170: Move _Py_GetAllocatedBlocks() and _PyObject_DebugMallocStats() private functions to the internal C API. Patch by Victor Stinner.
bpo-46433: The internal function _PyType_GetModuleByDef now correctly handles inheritance patterns involving static types.
bpo-45459:
Py_buffer
and variousPy_buffer
related functions are now part of the limited API and stable ABI.bpo-14916: Fixed bug in the tokenizer that prevented
PyRun_InteractiveOne
from parsing from the provided FD.
Python 3.11.0 alpha 4¶
Release date: 2022-01-13
Core and Builtins¶
bpo-46070:
Py_EndInterpreter()
now explicitly untracks all objects currently tracked by the GC. Previously, if an object was used later by another interpreter, callingPyObject_GC_UnTrack()
on the object crashed if the previous or the next object of thePyGC_Head
structure became a dangling pointer. Patch by Victor Stinner.bpo-46347: Fix memory leak in PyEval_EvalCodeEx.
bpo-46339: Fix a crash in the parser when retrieving the error text for multi-line f-strings expressions that do not start in the first line of the string. Patch by Pablo Galindo
bpo-46331: Do not set line number of instruction storing doc-string. Fixes regression introduced in 3.11 alpha.
bpo-46314: Remove spurious “call” event when creating a lambda function that was accidentally introduced in 3.11a4.
bpo-46289: ASDL declaration of
FormattedValue
has changed to reflectconversion
field is not optional.bpo-46297: Fixed an interpreter crash on bootup with multiple PythonPaths set in the Windows registry. Patch by Derzsi Dániel.
bpo-46237: Fix the line number of tokenizer errors inside f-strings. Patch by Pablo Galindo.
bpo-46263: We always expect the “use_frozen_modules” config to be set, now that getpath.c was rewritten in pure Python and the logic improved.
bpo-46006: Fix a regression when a type method like
__init__()
is modified in a subinterpreter. Fix a regression in_PyUnicode_EqualToASCIIId()
and typeupdate_slot()
. Revert the change which made the Unicode dictionary of interned strings compatible with subinterpreters: the internal interned dictionary is shared again by all interpreters. Patch by Victor Stinner.bpo-45923: Add RESUME opcode. This is a logical no-op. It is emitted by the compiler anywhere a Python function can be entered. It is used by the interpreter to perform tracing and optimizer checks.
bpo-46208: Fix the regression of os.path.normpath(“A/../../B”) not returning expected “../B” but “B”.
bpo-46240: Correct the error message for unclosed parentheses when the tokenizer doesn’t reach the end of the source when the error is reported. Patch by Pablo Galindo
bpo-46009: Remove the
GEN_START
opcode.bpo-46235: Certain sequence multiplication operations like
[0] * 1_000
are now faster due to reference-counting optimizations. Patch by Dennis Sweeney.bpo-46221:
PREP_RERAISE_STAR
no longer pusheslasti
to the stack.bpo-46202: Remove
POP_EXCEPT_AND_RERAISE
and replace it by an equivalent sequence of other opcodes.bpo-46085: Fix iterator cache mechanism of
OrderedDict
.bpo-46055: Speed up shifting operation involving integers less than
PyLong_BASE
. Patch by Xinhang Xu.bpo-46110: Add a maximum recursion check to the PEG parser to avoid stack overflow. Patch by Pablo Galindo
bpo-46107: Fix bug where
ExceptionGroup.split()
andExceptionGroup.subgroup()
did not copy the exception group’s__note__
field to the parts.bpo-45711: The interpreter state’s representation of handled exceptions (a.k.a exc_info, or _PyErr_StackItem) now has only the
exc_value
field,exc_type
andexc_traceback
have been removed as their values can be derived fromexc_value
.bpo-44525: Replace the four call bytecode instructions which one pre-call instruction and two call instructions.
Removes
CALL_FUNCTION
,CALL_FUNCTION_KW
,CALL_METHOD
andCALL_METHOD_KW
.Adds
CALL_NO_KW
andCALL_KW
call instructions, andPRECALL_METHOD
prefix for pairing withLOAD_METHOD
.bpo-46039: Remove the
YIELD_FROM
instruction and replace it with theSEND
instruction which performs the same operation, but without the loop.bpo-45635: The code called from
_PyErr_Display()
was refactored to improve error handling. It now exits immediately upon an unrecoverable error.bpo-46054: Fix parser error when parsing non-utf8 characters in source files. Patch by Pablo Galindo.
bpo-46042: Improve the location of the caret in
SyntaxError
exceptions emitted by the symbol table. Patch by Pablo Galindo.bpo-46049: Ensure
._pth
files work as intended on platforms other than Windows.bpo-46048: Fixes parsing of
._pth
files on startup so that single-character paths are correctly read.bpo-37971: Fix a bug where the line numbers given in a traceback when a decorator application raised an exception were wrong.
bpo-46031: Add
POP_JUMP_IF_NOT_NONE
andPOP_JUMP_IF_NONE
opcodes to speed up conditional jumps.bpo-46025: Fix a crash in the
atexit
module involving functions that unregister themselves before raising exceptions. Patch by Pablo Galindo.bpo-46000: Improve compatibility of the
curses
module with NetBSD curses.bpo-44525: Specialize the CALL_FUNCTION instruction for calls to builtin types with a single argument. Speeds up
range(x)
,list(x)
, and specificallytype(obj)
.bpo-42918: Fix bug where the built-in
compile()
function did not always raise aSyntaxError
when passed multiple statements in ‘single’ mode. Patch by Weipeng Hong.bpo-45953: The main interpreter in _PyRuntimeState.interpreters is now statically allocated (as part of _PyRuntime). Likewise for the initial thread state of each interpreter. This means less allocation during runtime init, as well as better memory locality for these key state objects.
bpo-45292: Complete the PEP 654 implementation: add
except*
.bpo-43413: Revert changes in
set.__init__
. Subclass ofset
needs to define a__init__()
method if it defines a__new__()
method with additional keyword parameters.bpo-43931: Added the
Py_Version
constant which bears the same value asPY_VERSION_HEX
. Patch by Gabriele N. Tornetta.
Library¶
bpo-46342: The
@typing.final
decorator now sets the__final__
attribute on the decorated object to allow runtime introspection. Patch by Jelle Zijlstra.bpo-46328: Added the
sys.exception()
method which returns the active exception instance.bpo-46307: Add
string.Template.is_valid()
andstring.Template.get_identifiers()
methods.bpo-46306: Assume that
types.CodeType
always hastypes.CodeType.co_firstlineno
indoctest
.bpo-40479: Fix
hashlib
usedforsecurity option to work correctly with OpenSSL 3.0.0 in FIPS mode.bpo-46070: Fix possible segfault when importing the
asyncio
module from different sub-interpreters in parallel. Patch by Erlend E. Aasland.bpo-46244: Removed
__slots__
fromtyping.ParamSpec
andtyping.TypeVar
. They served no purpose. Patch by Arie Bovenberg.bpo-46278: Reflect
context
argument inAbstractEventLoop.call_*()
methods. Loop implementations already support it.bpo-46269: Remove special-casing of
__new__
inenum.Enum.__dir__()
.bpo-46266: Improve day constants in
calendar
.Now all constants (
MONDAY
…SUNDAY
) are documented, tested, and added to__all__
.bpo-46257: Optimized the mean, variance, and stdev functions in the statistics module. If the input is an iterator, it is consumed in a single pass rather than eating memory by conversion to a list. The single pass algorithm is about twice as fast as the previous two pass code.
bpo-41011: Added two new variables to pyvenv.cfg which is generated by
venv
module: executable for the executable and command for the command line used to create the environment.bpo-46239: Improve error message when importing
asyncio.windows_events
on non-Windows.bpo-46238: Reuse
_winapi
constants inasyncio.windows_events
.bpo-46222: Adding
SF_NOCACHE
sendfile constant for FreeBSD for the posixmodule.bpo-37295: Add fast path for
0 <= k <= n <= 67
formath.comb()
.bpo-46176: Adding the
MAP_STACK
constant for the mmap module.bpo-43424: Deprecate
webbrowser.MacOSXOSAScript._name
and usename
instead.bpo-45321: Added missing error codes to module
xml.parsers.expat.errors
.bpo-46125: Refactor tests to test traversable API directly. Includes changes from importlib 5.4.0.
bpo-46118: Moved importlib.resources and its related functionality to a package.
bpo-37578: Add include_hidden parameter to
glob()
andiglob()
to match hidden files and directories when using special characters like*
,**
,?
and[]
.bpo-20369:
concurrent.futures.wait()
no longer blocks forever when given duplicate Futures. Patch by Kumar Aditya.bpo-46105: Honor spec when generating requirement specs with urls and extras (importlib_metadata 4.8.3).
bpo-44893: EntryPoint objects are no longer tuples. Recommended means to access is by attribute (‘.name’, ‘.group’) or accessor (‘.load()’). Access by index is deprecated and will raise deprecation warning.
bpo-22815: Print unexpected successes together with failures and errors in summary in
unittest.TextTestResult
.bpo-22047: Calling
add_argument_group()
on an argument group is deprecated. Callingadd_argument_group()
oradd_mutually_exclusive_group()
on a mutually exclusive group is deprecated.These features were never supported and do not always work correctly. The functions exist on the API by accident through inheritance and will be removed in the future.
bpo-26952:
argparse
raisesValueError
with clear message when trying to render usage for an empty mutually-exclusive group. Previously it raised a crypticIndexError
.bpo-45615: Functions in the
traceback
module raiseTypeError
rather thanAttributeError
when an exception argument is not of typeBaseException
.bpo-16594: Add allow allow_reuse_port flag in socketserver.
bpo-27718: Fix help for the
signal
module. Some functions (e.g.signal()
andgetsignal()
) were omitted.bpo-46032: The
registry()
method offunctools.singledispatch()
functions checks now the first argument or the first parameter annotation and raises a TypeError if it is not supported. Previously unsupported “types” were ignored (e.g.typing.List[int]
) or caused an error at calling time (e.g.list[int]
).bpo-46014: Add ability to use
typing.Union
andtypes.UnionType
as dispatch argument tofunctools.singledispatch
. Patch provided by Yurii Karabas.bpo-46018: Ensure that
math.expm1()
does not raise on underflow.bpo-46016: Adding
F_DUP2FD
andF_DUP2FD_CLOEXEC
constants from FreeBSD into the fcntl module.bpo-45755:
typing
generic aliases now reveal the class attributes of the original generic class when passed todir()
. This was the behavior up to Python 3.6, but was changed in 3.7-3.9.bpo-45874: The empty query string, consisting of no query arguments, is now handled correctly in
urllib.parse.parse_qsl
. This caused problems before when strict parsing was enabled.bpo-44674: Change how dataclasses disallows mutable default values. It used to use a list of known types (list, dict, set). Now it disallows unhashable objects to be defaults. It’s using unhashability as a proxy for mutability. Patch by Eric V. Smith, idea by Raymond Hettinger.
bpo-23882: Remove namespace package (PEP 420) support from unittest discovery. It was introduced in Python 3.4 but has been broken since Python 3.7.
bpo-25066: Added a
__repr__()
method tomultiprocessing.Event
objects, patch by Kumar Aditya.bpo-45643: Added
signal.SIGSTKFLT
on platforms where this signal is defined.bpo-44092: Fetch across rollback no longer raises
InterfaceError
. Instead we leave it to the SQLite library to handle these cases. Patch by Erlend E. Aasland.bpo-42413: Replace
concurrent.futures.TimeoutError
andasyncio.TimeoutError
with builtinTimeoutError
, keep these names as deprecated aliases.
Documentation¶
Tests¶
bpo-46296: Add a test case for
enum
with_use_args_ == True
and_member_type_ == object
.bpo-46205: Fix hang in runtest_mp due to race condition
bpo-46263: Fix test_capi on FreeBSD 14-dev: instruct jemalloc to not fill freed memory with junk byte.
bpo-46262: Cover
ValueError
path in tests forenum.Flag._missing_()
.bpo-46150: Now
fakename
intest_pathlib.PosixPathTest.test_expanduser
is checked to be non-existent.bpo-46129: Rewrite
asyncio.locks
tests withunittest.IsolatedAsyncioTestCase
usage.bpo-23819: Fixed
asyncio
tests in python optimized mode. Patch by Kumar Aditya.bpo-46114: Fix test case for OpenSSL 3.0.1 version. OpenSSL 3.0 uses
0xMNN00PP0L
.
Build¶
bpo-44133: When Python is configured with
--without-static-libpython
, the Python static library (libpython.a) is no longer built. Patch by Victor Stinner.bpo-44133: When Python is built without
--enable-shared
, thepython
program is now linked to object files, rather than being linked to the Python static library (libpython.a), to make sure that all symbols are exported. Previously, the linker omitted some symbols like thePy_FrozenMain()
function. Patch by Victor Stinner.bpo-40280: The
configure
script has a new option--with-emscripten-target
to select browser or node as Emscripten build target.bpo-46315: Added and fixed
#ifdef HAVE_FEATURE
checks for functionality that is not available on WASI platform.bpo-45723: Fixed a regression in
configure
check forselect.epoll()
.bpo-46263:
configure
no longer setsMULTIARCH
on FreeBSD platforms.bpo-46106: Updated OpenSSL to 1.1.1m in Windows builds, macOS installer builds, and CI. Patch by Kumar Aditya.
bpo-46088: Automatically detect or install bootstrap Python runtime when building from Visual Studio.
bpo-46072: Add a –with-pystats configure option to turn on internal statistics gathering.
bpo-40280: A new directory
Tools/wasm
contains WebAssembly-related helpers likeconfig.site
override for wasm32-emscripten, wasm assets generator to bundle the stdlib, and a README.bpo-46023: makesetup no longer builds extensions that have been marked as disabled. This allows users to disable modules in
Modules/Setup.local
.bpo-45949: Use pure Python
freeze_module
for all but importlib bootstrap files.--with-freeze-module
configure option is no longer needed for cross builds.
Windows¶
bpo-46217: Removed parameter that is unsupported on Windows 8.1 and early Windows 10 and may have caused build or runtime failures.
macOS¶
bpo-40477: The Python Launcher app for macOS now properly launches scripts and, if necessary, the Terminal app when running on recent macOS releases.
C API¶
bpo-46236: Fix a bug in
PyFunction_GetAnnotations()
that caused it to return atuple
instead of adict
.bpo-46140:
PyBuffer_GetPointer()
,PyBuffer_FromContiguous()
,PyBuffer_ToContiguous()
andPyMemoryView_FromBuffer()
now take buffer info byconst Py_buffer *
instead ofPy_buffer *
, as they do not need mutability.PyBuffer_FromContiguous()
also now takes the source buffer asconst void *
, and similarlyPyBuffer_GetPointer()
takes the strides asconst Py_ssize_t *
.bpo-45855: Document that the no_block argument to
PyCapsule_Import()
is a no-op now.bpo-45855: Replaced deprecated usage of
PyImport_ImportModuleNoBlock()
withPyImport_ImportModule()
in stdlib modules. Patch by Kumar Aditya.bpo-46007: The
PyUnicode_CHECK_INTERNED()
macro has been excluded from the limited C API. It was never usable there, because it used internal structures which are not available in the limited C API. Patch by Victor Stinner.
Python 3.11.0 alpha 3¶
Release date: 2021-12-08
Core and Builtins¶
bpo-46009: Restore behavior from 3.9 and earlier when sending non-None to newly started generator. In 3.9 this did not affect the state of the generator. In 3.10.0 and 3.10.1
gen_func().send(0)
is equivalent togen_func().throw(TypeError(...)
which exhausts the generator. In 3.10.2 onward, the behavior has been reverted to that of 3.9.bpo-46004: Fix the
SyntaxError
location for errors involving for loops with invalid targets. Patch by Pablo Galindobpo-45711:
_PyErr_ChainStackItem()
no longer normalizesexc_info
(including setting the traceback on the exception instance) becauseexc_info
is always normalized.bpo-45607: The
__note__
field was added toBaseException
. It isNone
by default but can be set to a string which is added to the exception’s traceback.bpo-45947: Place pointers to dict and values immediately before GC header. This reduces number of dependent memory loads to access either dict or values from 3 to 1.
bpo-45915:
is_valid_fd
now uses fasterfcntl(fd, F_GETFD)
on Linux, macOS, and Windows.bpo-44530: Reverts a change to the
code.__new__
audit event from an earlier prerelease.bpo-42268: Fail the configure step if the selected compiler doesn’t support memory sanitizer. Patch by Pablo Galindo
bpo-45711: The three values of
exc_info
are now always consistent with each other. In particular, thetype
andtraceback
fields are now derived from the exception instance. This impacts the return values ofsys.exc_info()
andPyErr_GetExcInfo()
if the exception instance is modified while the exception is handled, as well asPyErr_SetExcInfo()
, which now ignores thetype
andtraceback
arguments provided to it.bpo-45727: Refine the custom syntax error that suggests that a comma may be missing to trigger only when the expressions are detected between parentheses or brackets. Patch by Pablo Galindo
bpo-45885: Specialized the
COMPARE_OP
opcode using the PEP 659 machinery.bpo-45786: Allocate space for the interpreter frame in the frame object, to avoid an additional allocation when the frame object outlives the frame activation.
bpo-45614: Fix
traceback
display for exceptions with invalid module name.bpo-45813: Fix crash when calling coro.cr_frame.clear() after coroutine has been freed.
bpo-45811: Improve the tokenizer errors when encountering invisible control characters in the parser. Patch by Pablo Galindo
bpo-45848: Allow the parser to obtain error lines directly from encoded files. Patch by Pablo Galindo
bpo-45709: Restore behavior from 3.10 when tracing an exception raised within a with statement.
bpo-44525: Adds new
COPY_FREE_VARS
opcode, to make copying of free variables from function to frame explicit. Helps optimization of calls to Python function.bpo-45829: Specialize
BINARY_SUBSCR
for classes with a__getitem__
method implemented in Pythonbpo-45826: Fixed a crash when calling
.with_traceback(None)
onNameError
. This occurs internally inunittest.TestCase.assertRaises()
.bpo-45822: Fixed a bug in the parser that was causing it to not respect PEP 263 coding cookies when no flags are provided. Patch by Pablo Galindo
bpo-45820: Fix a segfault when the parser fails without reading any input. Patch by Pablo Galindo
bpo-45636: Simplify the implementation of
BINARY_OP
by indexing into an array of function pointers (rather than switching on the oparg).bpo-42540: Fix crash when
os.fork()
is called with an active non-default memory allocator.bpo-45738: Fix computation of error location for invalid continuation characters in the parser. Patch by Pablo Galindo.
bpo-45636: Remove an existing “fast path” for old-style string formatting, since it no longer appears to have any measurable impact.
bpo-45753: Make recursion checks a bit more efficient by tracking amount of calls left before overflow.
bpo-45773: Fix a compiler hang when attempting to optimize certain jump patterns.
bpo-45764: The parser now gives a better error message when leaving out the opening parenthesis
(
after adef
-statement:>>> def f: File "<stdin>", line 1 def f: ^ SyntaxError: expected '('
bpo-45609: Specialized the
STORE_SUBSCR
opcode using the PEP 659 machinery.bpo-45636: Replace all numeric
BINARY_*
andINPLACE_*
instructions with a singleBINARY_OP
implementation.bpo-45582: Path calculation (known as
getpath
) has been reimplemented as a frozen Python module. This should have no visible impact, but may affect calculation of all paths referenced insys
andsysconfig
.bpo-45450: Improve the syntax error message for parenthesized arguments. Patch by Pablo Galindo.
Library¶
bpo-27946: Fix possible crash when getting an attribute of class:
xml.etree.ElementTree.Element
simultaneously with replacing theattrib
dict.bpo-45711: Make
asyncio
normalize exceptions as soon as they are captured withPyErr_Fetch()
, and before they are stored as an exc_info triplet. This bringsasyncio
in line with the rest of the codebase, where an exc_info triplet is always normalized.bpo-23819: Replaced asserts with exceptions in asyncio, patch by Kumar Aditya.
bpo-13236:
unittest.TextTestResult
andunittest.TextTestRunner
flush now the output stream more often.bpo-45917: Added
math.exp2()
:, which returns 2 raised to the power of x.bpo-37658: Fix issue when on certain conditions
asyncio.wait_for()
may allow a coroutine to complete successfully, but fail to return the result, potentially causing memory leaks or other issues.bpo-45876: Improve the accuracy of stdev() and pstdev() in the statistics module. When the inputs are floats or fractions, the output is a correctly rounded float
bpo-44649: Handle dataclass(slots=True) with a field that has default a default value, but for which init=False.
bpo-45803: Added missing kw_only parameter to dataclasses.make_dataclass().
bpo-45837: The
turtle.RawTurtle.settiltangle()
is deprecated since Python 3.1, it now emits a deprecation warning and will be removed in Python 3.13.Use
turtle.RawTurtle.tiltangle()
instead.turtle.RawTurtle.tiltangle()
was earlier incorrectly marked as deprecated, its docstring has been corrected.Patch by Hugo van Kemenade.
bpo-45831:
faulthandler
can now write ASCII-only strings (like filenames and function names) with a single write() syscall when dumping a traceback. It reduces the risk of getting an unreadable dump when two threads or two processes dump a traceback to the same file (like stderr) at the same time. Patch by Victor Stinner.bpo-45828:
sqlite
C callbacks now use unraisable exceptions if callback tracebacks are enabled. Patch by Erlend E. Aasland.bpo-41735: Fix thread lock in
zlib.Decompress.flush()
method beforePyObject_GetBuffer
.bpo-45235: Reverted an argparse bugfix that caused regression in the handling of default arguments for subparsers. This prevented leaf level arguments from taking precedence over root level arguments.
bpo-45754: Fix a regression in Python 3.11a1 and 3.11a2 where
sqlite3
incorrectly would useSQLITE_LIMIT_LENGTH
when checking SQL statement lengths. Now,SQLITE_LIMIT_SQL_LENGTH
is used. Patch by Erlend E. Aasland.bpo-45766: Added proportional option to
statistics.linear_regression()
.bpo-45765: In importlib.metadata, fix distribution discovery for an empty path.
bpo-45757: Fix bug where
dis
produced an incorrect oparg whenEXTENDED_ARG
is followed by an opcode that does not use its argument.bpo-45644: In-place JSON file formatting using
python3 -m json.tool infile infile
now works correctly, previously it left the file empty. Patch by Chris Wesseling.bpo-45703: When a namespace package is imported before another module from the same namespace is created/installed in a different
sys.path
location while the program is running, calling theimportlib.invalidate_caches()
function will now also guarantee the new module is noticed.bpo-45535: Improve output of
dir()
with Enums.bpo-45664: Fix
types.resolve_bases()
andtypes.new_class()
fortypes.GenericAlias
instance as a base.bpo-45663: Fix
dataclasses.is_dataclass()
for dataclasses which are subclasses oftypes.GenericAlias
.bpo-45662: Fix the repr of
dataclasses.InitVar
with a type alias to the built-in class, e.g.InitVar[list[int]]
.bpo-43137: Launch GNOME web browsers via gio tool instead of obsolete gvfs-open
bpo-45429: On Windows,
time.sleep()
now uses a waitable timer which supports high-resolution timers. Patch by Dong-hee Na and Eryk Sun.bpo-37295: Optimize
math.comb()
andmath.perm()
.bpo-45514: Deprecated legacy functions in
importlib.resources
.bpo-45507: Add tests for truncated/missing trailers in gzip.decompress implementation.
bpo-45359: Implement PEP 585 for
graphlib.TopologicalSorter
.bpo-44733: Add
max_tasks_per_child
toconcurrent.futures.ProcessPoolExecutor
. This allows users to specify the maximum number of tasks a single process should execute before the process needs to be restarted.bpo-28806: Improve netrc library. netrc file no longer needs to contain all tokens. And if the login name is anonymous, security check is no longer need.
bpo-43498: Avoid a possible “RuntimeError: dictionary changed size during iteration” when adjusting the process count of
ProcessPoolExecutor
.bpo-42158: Add MIME types for N-quads, N-triples, Notation3 and TriG to
mimetypes
.bpo-30533: Add
inspect.getmembers_static()
, it return all members without triggering dynamic lookup via the descriptor protocol. Patch by Weipeng Hong.
Documentation¶
bpo-42238:
make -C Doc suspicious
will be removed soon in favor ofmake -C Doc check
, mark it as deprecated.bpo-45840: Improve cross-references in the documentation for the data model.
bpo-45640: Properly marked-up grammar tokens in the documentation are now clickable and take you to the definition of a given piece of grammar. Patch by Arthur Milchior.
bpo-45788: Link doc for sys.prefix to sysconfig doc on installation paths.
bpo-45772:
socket.socket
documentation is corrected to a class from a function.bpo-45392: Update the docstring of the
type
built-in to remove a redundant line and to mention keyword arguments for the constructor.bpo-45250: Update the documentation to note that CPython does not consistently require iterators to define
__iter__
.bpo-25381: In the extending chapter of the extending doc, update a paragraph about the global variables containing exception information.
bpo-43905: Expanded
astuple()
andasdict()
docs, warning about deepcopy being applied and providing a workaround.
Tests¶
bpo-45695: Out-of-tree builds with a read-only source directory are now tested by CI.
bpo-19460: Add new Test for
Lib/email/mime/nonmultipart.py::MIMENonMultipart
.bpo-45835: Fix race condition in test_queue tests with multiple “feeder” threads.
bpo-45783: The test for the freeze tool now handles file moves and deletions.
bpo-45745: Remove the
--findleaks
command line option of regrtest: use the--fail-env-changed
option instead. Since Python 3.7, it was a deprecated alias to the--fail-env-changed
option.bpo-45701: Add tests with
tuple
type withfunctools.lru_cache()
totest_functools
.
Build¶
bpo-44035: CI now verifies that autoconf files have been regenerated with a current and unpatched autoconf package.
bpo-45950: The build system now uses a _bootstrap_python interpreter for freezing and deepfreezing again. To speed up build process the build tools _bootstrap_python and _freeze_module are no longer build with LTO.
bpo-45881: The configure script now accepts
--with-build-python
and--with-freeze-module
options to make cross compiling easier.bpo-40280: Emscripten platform now uses
.wasm
suffix by default.bpo-40280: Disable unusable core extension modules on WASM/Emscripten targets.
bpo-40280:
configure
now checks for socketshutdown
function. The check makes it possible to disableSYS_shutdown
withac_cv_func_shutdown=no
in CONFIG_SITE.bpo-40280:
configure
now checks for functionsfork1, getegid, geteuid, getgid, getppid, getuid, opendir, pipe, system, wait, ttyname
.bpo-33393: Update
config.guess
to 2021-06-03 andconfig.sub
to 2021-08-14.Makefile
now has anupdate-config
target to make updating more convenient.bpo-45866:
make regen-all
now produces the same output when run from a directory other than the source tree: when building Python out of the source tree. pegen now strips directory of the “generated by pygen from <FILENAME>” header Patch by Victor Stinner.bpo-40280:
configure
now accepts machinewasm32
orwasm64
and OSwasi
oremscripten
for cross building, e.g.wasm32-unknown-emscripten
,wasm32-wasi
, orwasm32-unknown-wasi
.bpo-41498: Python now compiles on platforms without
sigset_t
. Several functions insignal
are not available whensigset_t
is missing.Based on patch by Roman Yurchak for pyodide.
bpo-45881:
setup.py
now usesCC
from environment first to discover multiarch and cross compile paths.bpo-45886: The
_freeze_module
program path can now be overridden on the command line, e.g.make FREEZE_MODULE=../x86_64/Program/_freeze_module
.bpo-45873: Get rid of the
_bootstrap_python
build step. The deepfreeze.py script is now run using$(PYTHON_FOR_REGEN)
which can be Python 3.7 or newer (on Windows, 3.8 or newer).bpo-45847: Port builtin hashlib extensions to
PY_STDLIB_MOD
macro andaddext()
.bpo-45723: Add
autoconf
helpers for saving and restoring environment variables:SAVE_ENV
: Save$CFLAGS
,$LDFLAGS
,$LIBS
, and$CPPFLAGS
.RESTORE_ENV
: Restore$CFLAGS
,$LDFLAGS
,$LIBS
, and$CPPFLAGS
.WITH_SAVE_ENV([SCRIPT])
: RunSCRIPT
wrapped withSAVE_ENV
andRESTORE_ENV
.
Patch by Erlend E. Aasland.
bpo-45573: Mandatory core modules, that are required to bootstrap Python, are now in
Modules/Setup.bootstrap
.bpo-45573:
configure
now createsModules/Setup.stdlib
with conditionally enabled/disabled extension module lines. The file is not used, yet.bpo-45573:
configure
now uses a unified format to set state, compiler flags, and linker flags in Makefile. The new macroPY_STDLIB_MOD
sets three variables that are consumed byModules/Setup
andsetup.py
.bpo-45816: Python now supports building with Visual Studio 2022 (MSVC v143, VS Version 17.0). Patch by Jeremiah Vivian.
bpo-45800: Settings for
pyexpat
C extension are now detected byconfigure
. The bundledexpat
library is built inMakefile
.bpo-45798: Settings for
decimal
internal C extension are now detected byconfigure
. The bundledlibmpdec
library is built inMakefile
.bpo-45723: configure has a new option
--with-pkg-config
to disable or require pkg-config.bpo-45774: The build dependencies for
sqlite3
are now detected byconfigure
andpkg-config
. Patch by Erlend E. Aasland.bpo-45763: The build dependencies for
zlib
,bz2
, andlzma
are now detected byconfigure
.bpo-45747: gdbm and dbm build dependencies are now detected by
configure
.bpo-45743: On macOS, the build system no longer passes
search_paths_first
to the linker. The flag has been the default since Xcode 4 / macOS 10.6.bpo-45723:
configure.ac
is now compatible with autoconf 2.71. Deprecated checksSTDC_HEADERS
andAC_HEADER_TIME
have been removed.bpo-45723:
configure
now prints a warning when pkg-config is missing.bpo-45731:
configure --enable-loadable-sqlite-extensions
is now handled by newPY_SQLITE_ENABLE_LOAD_EXTENSION
macro instead of logic in setup.py.bpo-45723: configure.ac now uses custom helper macros and
AC_CACHE_CHECK
to simplify and speed up configure runs.bpo-45696: Skip the marshal step for frozen modules by generating C code that produces a set of ready-to-use code objects. This speeds up startup time by another 10% or more.
bpo-45561: Run smelly.py tool from $(srcdir).
Windows¶
bpo-46105: Fixed calculation of
sys.path
in a venv on Windows.bpo-45901: When installed through the Microsoft Store and set as the default app for
*.py
files, command line arguments will now be passed to Python when invoking a script without explicitly launching Python (that is,script.py args
rather thanpython script.py args
).bpo-45616: Fix Python Launcher’s ability to distinguish between versions 3.1 and 3.10 when either one is explicitly requested. Previously, 3.1 would be used if 3.10 was requested but not installed, and 3.10 would be used if 3.1 was requested but 3.10 was installed.
bpo-45850: Implement changes to build with deep-frozen modules on Windows. Note that we now require Python 3.10 as the “bootstrap” or “host” Python.
bpo-45732: Updates bundled Tcl/Tk to 8.6.12.
bpo-45720: Internal reference to
shlwapi.dll
was dropped to help improve startup time. This DLL will no longer be loaded at the start of every Python process.
macOS¶
bpo-45732: Update python.org macOS installer to use Tcl/Tk 8.6.12.
C API¶
bpo-39026: Fix Python.h to build C extensions with Xcode: remove a relative include from
Include/cpython/pystate.h
.
Python 3.11.0 alpha 2¶
Release date: 2021-11-05
Core and Builtins¶
bpo-45716: Improve the
SyntaxError
message when usingTrue
,None
orFalse
as keywords in a function call. Patch by Pablo Galindo.bpo-45688:
sys.stdlib_module_names
now contains the macOS-specific module_scproxy
.bpo-45379: Clarify
ImportError
message when we try to explicitly import a frozen module but frozen modules are disabled.bpo-44525: Specialize simple calls to Python functions (no starargs, keyowrd dict, or closure)
bpo-45530: Cases of sorting using tuples as keys may now be significantly faster in some cases. Patch by Tim Peters.
The order of the result may differ from earlier releases if the tuple elements don’t define a total ordering (see Value comparisons for information on total ordering). It’s generally true that the result of sorting simply isn’t well-defined in the absence of a total ordering on list elements.
bpo-45526: In obmalloc, set ADDRESS_BITS to not ignore any bits (ignored 16 before). That is safer in the case that the kernel gives user-space virtual addresses that span a range greater than 48 bits.
bpo-30570: Fixed a crash in
issubclass()
from infinite recursion when searching pathological__bases__
tuples.bpo-45521: Fix a bug in the obmalloc radix tree code. On 64-bit machines, the bug causes the tree to hold 46-bits of virtual addresses, rather than the intended 48-bits.
bpo-45494: Fix parser crash when reporting errors involving invalid continuation characters. Patch by Pablo Galindo.
bpo-45445: Python now fails to initialize if it finds an invalid
-X
option in the command line. Patch by Pablo Galindo.bpo-45340: Object attributes are held in an array instead of a dictionary. An object’s dictionary are created lazily, only when needed. Reduces the memory consumption of a typical Python object by about 30%. Patch by Mark Shannon.
bpo-45408: Fix a crash in the parser when reporting tokenizer errors that occur at the same time unclosed parentheses are detected. Patch by Pablo Galindo.
bpo-29410: Add SipHash13 for string hash algorithm and use it by default.
bpo-45385: Fix reference leak from descr_check. Patch by Dong-hee Na.
bpo-45367: Specialized the
BINARY_MULTIPLY
opcode toBINARY_MULTIPLY_INT
andBINARY_MULTIPLY_FLOAT
using the PEP 659 machinery.bpo-21736: Frozen stdlib modules now have
__file__
to the .py file they would otherwise be loaded from, if possible. For packages,__path__
now has the correct entry instead of being an empty list, which allows unfrozen submodules to be imported. These are set only if the stdlib directory is known when the runtime is initialized. Note that the file at__file__
is not guaranteed to exist. None of this affects non-stdlib frozen modules nor, for now, frozen modules imported usingPyImport_ImportFrozenModule()
. Also, at the momentco_filename
is not updated for the module.bpo-45020: For frozen stdlib modules, record the original module name as
module.__spec__.loader_state.origname
. If the value is different thanmodule.__spec__.name
then the module was defined as an alias in Tools/scripts/freeze_modules.py. If it isNone
then the module comes from a source file outside the stdlib.bpo-45324: In FrozenImporter.find_spec(), we now preserve the information needed in exec_module() to load the module. This change mostly impacts internal details, rather than changing the importer’s behavior.
bpo-45292: Implement PEP 654. Add
ExceptionGroup
andBaseExceptionGroup
. Update traceback display code.bpo-40116: Change to the implementation of split dictionaries. Classes where the instances differ either in the exact set of attributes, or in the order in which those attributes are set, can still share keys. This should have no observable effect on users of Python or the C-API. Patch by Mark Shannon.
bpo-44050: Extensions that indicate they use global state (by setting
m_size
to -1) can again be used in multiple interpreters. This reverts to behavior of Python 3.8.bpo-44525: Setup initial specialization infrastructure for the
CALL_FUNCTION
opcode. Implemented initial specializations for C function calls:CALL_FUNCTION_BUILTIN_O
forMETH_O
flag.CALL_FUNCTION_BUILTIN_FAST
forMETH_FASTCALL
flag without keywords.CALL_FUNCTION_LEN
forlen(o)
.CALL_FUNCTION_ISINSTANCE
forisinstance(o, t)
.
bpo-44511: Improve the generated bytecode for class and mapping patterns.
bpo-43706: Speed up calls to
enumerate()
by using the PEP 590vectorcall
calling convention. Patch by Dong-hee Na.
Library¶
bpo-45679: Fix caching of multi-value
typing.Literal
.Literal[True, 2]
is no longer equal toLiteral[1, 2]
.bpo-42064: Convert
sqlite3
to multi-phase initialisation (PEP 489). Patches by Erlend E. Aasland.bpo-45438: Fix typing.Signature string representation for generic builtin types.
bpo-45613:
sqlite3
now setssqlite3.threadsafety
based on the default threading mode the underlying SQLite library has been compiled with. Patch by Erlend E. Aasland.bpo-45574: Fix warning about
print_escape
being unused.bpo-45581:
sqlite3.connect()
now correctly raisesMemoryError
if the underlying SQLite API signals memory error. Patch by Erlend E. Aasland.bpo-45557: pprint.pprint() now handles underscore_numbers correctly. Previously it was always setting it to False.
bpo-44019: Add
operator.call()
tooperator.__all__
. Patch by Kreusada.bpo-42174:
shutil.get_terminal_size()
now falls back to sane values if the column or line count are 0.bpo-35673: Improve the introspectability of the
__loader__
attribute for namespace packages.importlib.machinery.NamespaceLoader
is now public, and implements theimportlib.abc.InspectLoader
interface._NamespaceLoader
is kept for backward compatibility.bpo-45515: Add references to
zoneinfo
in thedatetime
documentation, mostly replacing outdated references todateutil.tz
. Change by Paul Ganssle.bpo-45475: Reverted optimization of iterating
gzip.GzipFile
,bz2.BZ2File
, andlzma.LZMAFile
(see bpo-43787) because it caused regression when user iterate them without having reference of them. Patch by Inada Naoki.bpo-45489: Update
ForwardRef
to support|
operator. Patch by Dong-hee Na.bpo-42222: Removed deprecated support for float arguments in randrange().
bpo-45428: Fix a regression in py_compile when reading filenames from standard input.
bpo-45467: Fix incremental decoder and stream reader in the “raw-unicode-escape” codec. Previously they failed if the escape sequence was split.
bpo-45461: Fix incremental decoder and stream reader in the “unicode-escape” codec. Previously they failed if the escape sequence was split.
bpo-45239: Fixed
email.utils.parsedate_tz()
crashing withUnboundLocalError
on certain invalid input instead of returningNone
. Patch by Ben Hoyt.bpo-45417: Fix quadratic behaviour in the enum module: Creation of enum classes with a lot of entries was quadratic.
bpo-45249: Fix the behaviour of
traceback.print_exc()
when displaying the caret when theend_offset
in the exception is set to 0. Patch by Pablo Galindobpo-45416: Fix use of
asyncio.Condition
with explicitasyncio.Lock
objects, which was a regression due to removal of explicit loop arguments. Patch by Joongi Kim.bpo-20028: Empty escapechar/quotechar is not allowed when initializing
csv.Dialect
. Patch by Vajrasky Kok and Dong-hee Na.bpo-44904: Fix bug in the
doctest
module that caused it to fail if a docstring included an example with aclassmethod
property
. Patch by Alex Waygood.bpo-45406: Make
inspect.getmodule()
catchFileNotFoundError
raised by :’func:inspect.getabsfile
, and returnNone
to indicate that the module could not be determined.bpo-45411: Add extensions for files containing subtitles - .srt & .vtt - to the mimetypes.py module.
bpo-10716: Migrated pydoc to HTML5 (without changing the look of it). Side effect is to update xmlrpc’s
ServerHTMLDoc
which now uses the CSS too. cgitb now relies less on pydoc (as it can’t use the CSS file).bpo-45262: Prevent use-after-free in asyncio. Make sure the cached running loop holder gets cleared on dealloc to prevent use-after-free in get_running_loop
bpo-45386: Make
xmlrpc.client
more robust to C runtimes where the underlying Cstrftime
function results in aValueError
when testing for year formatting options.bpo-20028: Improve error message of
csv.Dialect
when initializing. Patch by Vajrasky Kok and Dong-hee Na.bpo-45343: Update bundled pip to 21.2.4 and setuptools to 58.1.0
bpo-45328: Fixed
http.client.HTTPConnection
to work properly in OSs that don’t support theTCP_NODELAY
socket option.bpo-45243: Add
setlimit()
andgetlimit()
tosqlite3.Connection
for setting and getting SQLite limits by connection basis. Patch by Erlend E. Aasland.bpo-45320: Removed from the
inspect
module:- the
getargspec
function, deprecated since Python 3.0; use
inspect.signature()
orinspect.getfullargspec()
instead.
- the
the
formatargspec
function, deprecated since Python 3.5; use theinspect.signature()
function andSignature
object directly.the undocumented
Signature.from_callable
andSignature.from_function
functions, deprecated since Python 3.5; use theSignature.from_callable()
method instead.
Patch by Hugo van Kemenade.
bpo-45192: Fix the
tempfile._infer_return_type
function so that thedir
argument of thetempfile
functions accepts an object implementing theos.PathLike
protocol.Patch by Kyungmin Lee.
bpo-45160: When tracing a tkinter variable used by a ttk OptionMenu, callbacks are no longer made twice.
bpo-25625: Added non parallel-safe
chdir()
context manager to change the current working directory and then restore it on exit. Simple wrapper aroundchdir()
.bpo-24139: Add support for SQLite extended result codes in
sqlite3.Error
. Patch by Erlend E. Aasland.bpo-24444: Fixed an error raised in
argparse
help display when help for an option is set to 1+ blank spaces or when choices arg is an empty container.bpo-44547: Implement
Fraction.__int__
, so that afractions.Fraction
instancef
passes anisinstance(f, typing.SupportsInt)
check.bpo-40321: Adds support for HTTP 308 redirects to
urllib
. See RFC 7538 for details. Patch by Jochem Schulenklopper.bpo-10572: Move
sqlite3
tests to/Lib/test/test_sqlite3
. Patch by Erlend E. Aasland.bpo-41374: Ensure that
socket.TCP_*
constants are exposed on Cygwin 3.1.6 and greater.bpo-35970: Add help flag to the base64 module’s command line interface. Patch contributed by Robert Kuska.
Documentation¶
bpo-45726: Improve documentation for
functools.singledispatch()
andfunctools.singledispatchmethod
.bpo-45680: Amend the docs on
GenericAlias
objects to clarify that non-container classes can also implement__class_getitem__
. Patch contributed by Alex Waygood.bpo-45618: Update Sphinx version used to build the documentation to 4.2.0. Patch by Maciej Olko.
bpo-45655: Add a new “relevant PEPs” section to the top of the documentation for the
typing
module. Patch by Alex Waygood.bpo-45604: Add
level
argument tomultiprocessing.log_to_stderr
function docs.bpo-45516: Add protocol description to the
importlib.abc.TraversableResources
documentation.bpo-45464: Mention in the documentation of Built-in Exceptions that inheriting from multiple exception types in a single subclass is not recommended due to possible memory layout incompatibility.
bpo-45449: Add note about PEP 585 in
collections.abc
.bpo-45516: Add protocol description to the
importlib.abc.Traversable
documentation.bpo-20692: Add Programming FAQ entry explaining that int literal attribute access requires either a space after or parentheses around the literal.
Tests¶
bpo-45678: Add tests for scenarios in which
functools.singledispatchmethod
is stacked on top of a method that has already been wrapped by two other decorators. Patch by Alex Waygood.bpo-45578: Add tests for
dis.distb()
bpo-45678: Add tests to ensure that
functools.singledispatchmethod
correctly wraps the attributes of the target function.bpo-45668: PGO tests now pass when Python is built without test extension modules.
bpo-45577: Add subtests for all
pickle
protocols intest_zoneinfo
.bpo-45566: Fix
test_frozen_pickle
intest_dataclasses
to check allpickle
versions.bpo-43592:
test.libregrtest
now raises the soft resource limit for the maximum number of file descriptors when the default is too low for our test suite as was often the case on macOS.bpo-39679: Add more test cases for
@functools.singledispatchmethod
when combined with@classmethod
or@staticmethod
.bpo-45410: When libregrtest spawns a worker process, stderr is now written into stdout to keep messages order. Use a single pipe for stdout and stderr, rather than two pipes. Previously, messages were out of order which made analysis of buildbot logs harder Patch by Victor Stinner.
bpo-45402: Fix test_tools.test_sundry() when Python is built out of tree: fix how the freeze_modules.py tool locates the _freeze_module program. Patch by Victor Stinner.
bpo-45403: Fix test_sys.test_stdlib_dir() when Python is built outside the source tree: compare normalized paths. Patch by Victor Stinner.
bpo-45400: Fix test_name_error_suggestions_do_not_trigger_for_too_many_locals() of test_exceptions if a directory name contains “a1” (like “Python-3.11.0a1”): use a stricter regular expression. Patch by Victor Stinner.
Build¶
bpo-43158:
setup.py
now uses values from configure script to build the_uuid
extension module. Configure now detects util-linux’slibuuid
, too.bpo-45666: Fix warning of
swprintf
and%s
usage in_testembed.c
bpo-45548:
Modules/Setup
andModules/makesetup
have been improved. TheSetup
file now contains working rules for all extensions. Outdated comments have been removed. Rules defined bymakesetup
track dependencies correctly.bpo-45548: The
math
andcmath
implementation now require a C99 compatiblelibm
and no longer ship with workarounds for missing acosh, asinh, atanh, expm1, and log1p functions.bpo-45595:
setup.py
andmakesetup
now track build dependencies on all Python header files and module specific header files.bpo-45571:
Modules/Setup
now usePY_CFLAGS_NODIST
instead ofPY_CFLAGS
to compile shared modules.bpo-45570:
pyexpat
and_elementtree
no longer define obsolete macrosHAVE_EXPAT_CONFIG_H
andUSE_PYEXPAT_CAPI
.XML_POOR_ENTROPY
is now defined inexpat_config.h
.bpo-43974:
setup.py
no longer definesPy_BUILD_CORE_MODULE
. Instead every module, that uses the internal API, defines the macro.bpo-45548: Fill in missing entries in Modules/Setup.
bpo-45532: Update
sys.version
to usemain
as fallback information. Patch by Jeong YunWon.bpo-45536: The
configure
script now checks whether OpenSSL headers and libraries provide required APIs. Most common APIs are verified. The check detects outdated or missing OpenSSL. Failures do not stop configure.bpo-45221: Fixed regression in handling of
LDFLAGS
andCPPFLAGS
options whereargparse.parse_known_args()
could interpret an option as one of the built-in command line argument, for example-h
for help.bpo-45440: Building Python now requires a C99
<math.h>
header file providing the following functions:copysign()
,hypot()
,isfinite()
,isinf()
,isnan()
,round()
. Patch by Victor Stinner.bpo-45405: Prevent
internal configure error
when runningconfigure
with recent versions of non-Apple clang. Patch by David Bohman.bpo-45433: Avoid linking libpython with libcrypt.
Windows¶
bpo-43652: Update Tcl/Tk to 8.6.11, actually this time. The previous update incorrectly included 8.6.10.
bpo-45337: venv now warns when the created environment may need to be accessed at a different path, due to redirections, links or junctions. It also now correctly installs or upgrades components when the alternate path is required.
bpo-43851: Build SQLite
SQLITE_OMIT_AUTOINIT
on Windows. Patch by Erlend E. Aasland.
macOS¶
bpo-44828: Avoid tkinter file dialog failure on macOS 12 Monterey when using the Tk 8.6.11 provided by python.org macOS installers. Patch by Marc Culler of the Tk project.
IDLE¶
bpo-45495: Add context keywords ‘case’ and ‘match’ to completions list.
C API¶
bpo-29103:
PyType_FromSpec*
now copies the class name from the spec to a buffer owned by the class, so the original can be safely deallocated. Patch by Petr Viktorin.bpo-45522: The internal freelists for frame, float, list, dict, async generators, and context objects can now be disabled.
bpo-35134: Exclude
PyWeakref_GET_OBJECT()
from the limited C API. It never worked since thePyWeakReference
structure is opaque in the limited C API.bpo-35081: Move the
interpreteridobject.h
header file fromInclude/
toInclude/internal/
. It only provides private functions. Patch by Victor Stinner.bpo-35134: The non-limited API files
cellobject.h
,classobject.h
,context.h
,funcobject.h
,genobject.h
andlongintrepr.h
have been moved to theInclude/cpython
directory. Moreover, theeval.h
header file was removed. These files must not be included directly, as they are already included inPython.h
: Include Files. If they have been included directly, consider includingPython.h
instead. Patch by Victor Stinner.bpo-45474: The following items are no longer available when
Py_LIMITED_API
is defined:the
Py_MARSHAL_VERSION
macro
These are not part of the limited API.
Patch by Victor Stinner.
bpo-45434: Remove the
pystrhex.h
header file. It only contains private functions. C extensions should only include the main<Python.h>
header file. Patch by Victor Stinner.bpo-45440: Remove the
Py_FORCE_DOUBLE()
macro. It was used by thePy_IS_INFINITY()
macro. Patch by Victor Stinner.bpo-45434:
<Python.h>
no longer includes the header files<stdlib.h>
,<stdio.h>
,<errno.h>
and<string.h>
when thePy_LIMITED_API
macro is set to0x030b0000
(Python 3.11) or higher. C extensions should explicitly include the header files after#include <Python.h>
. Patch by Victor Stinner.bpo-41123: Remove
Py_UNICODE_COPY()
andPy_UNICODE_FILL()
macros, deprecated since Python 3.3. UsePyUnicode_CopyCharacters()
ormemcpy()
(wchar_t*
string), andPyUnicode_Fill()
functions instead. Patch by Victor Stinner.bpo-45412: Remove the following math macros using the
errno
variable:Py_ADJUST_ERANGE1()
Py_ADJUST_ERANGE2()
Py_OVERFLOWED()
Py_SET_ERANGE_IF_OVERFLOW()
Py_SET_ERRNO_ON_MATH_ERROR()
Patch by Victor Stinner.
bpo-45395: Custom frozen modules (the array set to
PyImport_FrozenModules
) are now treated as additions, rather than replacing all the default frozen modules. Frozen stdlib modules can still be disabled by setting the “code” field of the custom array entry to NULL.bpo-43760: Add new
PyThreadState_EnterTracing()
, andPyThreadState_LeaveTracing()
functions to the limited C API to suspend and resume tracing and profiling. Patch by Victor Stinner.bpo-44220:
PyStructSequence_UnnamedField
is added to the Stable ABI.
Python 3.11.0 alpha 1¶
Release date: 2021-10-05
Security¶
bpo-42278: Replaced usage of
tempfile.mktemp()
withTemporaryDirectory
to avoid a potential race condition.bpo-44600: Fix incorrect line numbers while tracing some failed patterns in match statements. Patch by Charles Burkland.
bpo-41180: Add auditing events to the
marshal
module, and stop raisingcode.__init__
events for every unmarshalled code object. Directly instantiated code objects will continue to raise an event, and audit event handlers should inspect or collect the raw marshal data. This reduces a significant performance overhead when loading from.pyc
files.bpo-44394: Update the vendored copy of libexpat to 2.4.1 (from 2.2.8) to get the fix for the CVE-2013-0340 “Billion Laughs” vulnerability. This copy is most used on Windows and macOS.
bpo-43124: Made the internal
putcmd
function insmtplib
sanitize input for presence of\r
and\n
characters to avoid (unlikely) command injection.bpo-44022:
http.client
now avoids infinitely reading potential HTTP headers after a100 Continue
status response from the server.
Core and Builtins¶
bpo-43760: The number of hardware branches per instruction dispatch is reduced from two to one by adding a special instruction for tracing. Patch by Mark Shannon.
bpo-45061: Add a deallocator to the bool type to detect refcount bugs in C extensions which call Py_DECREF(Py_True) or Py_DECREF(Py_False) by mistake. Detect also refcount bugs when the empty tuple singleton or the Unicode empty string singleton is destroyed by mistake. Patch by Victor Stinner.
bpo-24076: sum() was further optimised for summing up single digit integers.
bpo-45190: Update Unicode databases to Unicode 14.0.0.
bpo-45167: Fix deepcopying of
types.GenericAlias
objects.bpo-45155:
int.to_bytes()
andint.from_bytes()
now take a default value of"big"
for thebyteorder
argument.int.to_bytes()
also takes a default value of1
for thelength
argument.bpo-44219: Release the GIL while performing
isatty
system calls on arbitrary file descriptors. In particular, this affectsos.isatty()
,os.device_encoding()
andio.TextIOWrapper
. By extension,io.open()
in text mode is also affected. This change solves a deadlock inos.isatty()
. Patch by Vincent Michel in bpo-44219.bpo-44959: Added fallback to extension modules with ‘.sl’ suffix on HP-UX
bpo-45121: Fix issue where
Protocol.__init__
raisesRecursionError
when it’s called directly or viasuper()
. Patch provided by Yurii Karabas.bpo-44348: The deallocator function of the
BaseException
type now uses the trashcan mechanism to prevent stack overflow. For example, when aRecursionError
instance is raised, it can be linked to another RecursionError through the__context__
attribute or the__traceback__
attribute, and then a chain of exceptions is created. When the chain is destroyed, nested deallocator function calls can crash with a stack overflow if the chain is too long compared to the available stack memory. Patch by Victor Stinner.bpo-45123: Fix PyAiter_Check to only check for the __anext__ presence (not for __aiter__). Rename PyAiter_Check to PyAIter_Check, PyObject_GetAiter -> PyObject_GetAIter.
bpo-1514420: Interpreter no longer attempts to open files with names in angle brackets (like “<string>” or “<stdin>”) when formatting an exception.
bpo-41031: Match C and Python code formatting of unprintable exceptions and exceptions in the
__main__
module.bpo-37330:
open()
,io.open()
,codecs.open()
andfileinput.FileInput
no longer accept'U'
(“universal newline”) in the file mode. This flag was deprecated since Python 3.3. Patch by Victor Stinner.bpo-45083: When the interpreter renders an exception, its name now has a complete qualname. Previously only the class name was concatenated to the module name, which sometimes resulted in an incorrect full name being displayed.
(This issue impacted only the C code exception rendering, the
traceback
module was using qualname already).bpo-34561: List sorting now uses the merge-ordering strategy from Munro and Wild’s
powersort()
. Unlike the former strategy, this is provably near-optimal in the entropy of the distribution of run lengths. Most uses oflist.sort()
probably won’t see a significant time difference, but may see significant improvements in cases where the former strategy was exceptionally poor. However, as these are all fast linear-time approximations to a problem that’s inherently at best quadratic-time to solve truly optimally, it’s also possible to contrive cases where the former strategy did better.bpo-45056: Compiler now removes trailing unused constants from co_consts.
bpo-45020: Add a new command line option, “-X frozen_modules=[on|off]” to opt out of (or into) using optional frozen modules. This defaults to “on” (or “off” if it’s running out of the source tree).
bpo-45012: In
posix
, release GIL duringstat()
,lstat()
, andfstatat()
syscalls made byos.DirEntry.stat()
. Patch by Stanisław Skonieczny.bpo-45018: Fixed pickling of range iterators that iterated for over
2**32
times.bpo-45000: A
SyntaxError
is now raised when trying to delete__debug__
. Patch by Dong-hee Na.bpo-44963: Implement
send()
andthrow()
methods foranext_awaitable
objects. Patch by Pablo Galindo.bpo-44962: Fix a race in WeakKeyDictionary, WeakValueDictionary and WeakSet when two threads attempt to commit the last pending removal. This fixes asyncio.create_task and fixes a data loss in asyncio.run where shutdown_asyncgens is not run
bpo-24234: Implement the
__bytes__()
special method on thebytes
type, so a bytes objectb
passes anisinstance(b, typing.SupportsBytes)
check.bpo-24234: Implement the
__complex__()
special method on thecomplex
type, so a complex numberz
passes anisinstance(z, typing.SupportsComplex)
check.bpo-44954: Fixed a corner case bug where the result of
float.fromhex('0x.8p-1074')
was rounded the wrong way.bpo-44947: Refine the syntax error for trailing commas in import statements. Patch by Pablo Galindo.
bpo-44945: Specialize the BINARY_ADD instruction using the PEP 659 machinery. Adds five new instructions:
BINARY_ADD_ADAPTIVE
BINARY_ADD_FLOAT
BINARY_ADD_INT
BINARY_ADD_UNICODE
BINARY_ADD_UNICODE_INPLACE_FAST
bpo-44929: Fix some edge cases of
enum.Flag
string representation in the REPL. Patch by Pablo Galindo.bpo-44914: Class version tags are no longer recycled.
This means that a version tag serves as a unique identifier for the state of a class. We rely on this for effective specialization of the LOAD_ATTR and other instructions.
bpo-44698: Restore behaviour of complex exponentiation with integer-valued exponent of type
float
orcomplex
.bpo-44895: A debug variable
PYTHONDUMPREFSFILE
is added for creating a dump file which is generated by--with-trace-refs
. Patch by Dong-hee Na.bpo-44900: Add five superinstructions for PEP 659 quickening:
LOAD_FAST LOAD_FAST
STORE_FAST LOAD_FAST
LOAD_FAST LOAD_CONST
LOAD_CONST LOAD_FAST
STORE_FAST STORE_FAST
bpo-44889: Initial implementation of adaptive specialization of
LOAD_METHOD
. The following specialized forms were added:LOAD_METHOD_CACHED
LOAD_METHOD_MODULE
LOAD_METHOD_CLASS
bpo-44890: Specialization stats are always collected in debug builds.
bpo-44885: Correct the ast locations of f-strings with format specs and repeated expressions. Patch by Pablo Galindo
bpo-44878: Remove the loop from the bytecode interpreter. All instructions end with a DISPATCH macro, so the loop is now redundant.
bpo-44878: Remove switch statement for interpreter loop when using computed gotos. This makes sure that we only have one dispatch table in the interpreter.
bpo-44874: Deprecate the old trashcan macros (
Py_TRASHCAN_SAFE_BEGIN
/Py_TRASHCAN_SAFE_END
). They should be replaced by the new macrosPy_TRASHCAN_BEGIN
andPy_TRASHCAN_END
.bpo-44872: Use new trashcan macros (Py_TRASHCAN_BEGIN/END) in frameobject.c instead of the old ones (Py_TRASHCAN_SAFE_BEGIN/END).
bpo-33930: Fix segmentation fault with deep recursion when cleaning method objects. Patch by Augusto Goulart and Pablo Galindo.
bpo-25782: Fix bug where
PyErr_SetObject
hangs when the current exception has a cycle in its context chain.bpo-44856: Fix reference leaks in the error paths of
update_bases()
and__build_class__
. Patch by Pablo Galindo.bpo-44826: Initial implementation of adaptive specialization of STORE_ATTR
Three specialized forms of STORE_ATTR are added:
STORE_ATTR_SLOT
STORE_ATTR_SPLIT_KEYS
STORE_ATTR_WITH_HINT
bpo-44838: Fixed a bug that was causing the parser to raise an incorrect custom
SyntaxError
for invalid ‘if’ expressions. Patch by Pablo Galindo.bpo-44821: Create instance dictionaries (__dict__) eagerly, to improve regularity of object layout and assist specialization.
bpo-44792: Improve syntax errors for if expressions. Patch by Miguel Brito
bpo-34013: Generalize the invalid legacy statement custom error message (like the one generated when “print” is called without parentheses) to include more generic expressions. Patch by Pablo Galindo
bpo-44732: Rename
types.Union
totypes.UnionType
.bpo-44725: Expose specialization stats in python via
_opcode.get_specialization_stats()
.bpo-44717: Improve AttributeError on circular imports of submodules.
bpo-44698: Fix undefined behaviour in complex object exponentiation.
bpo-44653: Support
typing
types in parameter substitution in the union type.bpo-44676: Add ability to serialise
types.Union
objects. Patch provided by Yurii Karabas.bpo-44633: Parameter substitution of the union type with wrong types now raises
TypeError
instead of returningNotImplemented
.bpo-44661: Update
property_descr_set
to use vectorcall if possible. Patch by Dong-hee Na.bpo-44662: Add
__module__
totypes.Union
. This also fixestypes.Union
issues withtyping.Annotated
. Patch provided by Yurii Karabas.bpo-44655: Include the name of the type in unset __slots__ attribute errors. Patch by Pablo Galindo
bpo-44655: Don’t include a missing attribute with the same name as the failing one when offering suggestions for missing attributes. Patch by Pablo Galindo
bpo-44646: Fix the hash of the union type: it no longer depends on the order of arguments.
bpo-44636: Collapse union of equal types. E.g. the result of
int | int
is nowint
. Fix comparison of the union type with non-hashable objects. E.g.int | str == {}
no longer raises a TypeError.bpo-44611: On Windows,
os.urandom()
: uses BCryptGenRandom API instead of CryptGenRandom API which is deprecated from Microsoft Windows API. Patch by Dong-hee Na.bpo-44635: Convert
None
totype(None)
in the union type constructor.bpo-26280: Implement adaptive specialization for BINARY_SUBSCR
Three specialized forms of BINARY_SUBSCR are added:
BINARY_SUBSCR_LIST_INT
BINARY_SUBSCR_TUPLE_INT
BINARY_SUBSCR_DICT
bpo-44589: Mapping patterns in
match
statements with two or more equal literal keys will now raise aSyntaxError
at compile-time.bpo-44606: Fix
__instancecheck__
and__subclasscheck__
for the union type.bpo-42073: The
@classmethod
decorator can now wrap other classmethod-like descriptors.bpo-41972: Tuned the string-searching algorithm of fastsearch.h to have a shorter inner loop for most cases.
bpo-44590: All necessary data for executing a Python function (local variables, stack, etc) is now kept in a per-thread stack. Frame objects are lazily allocated on demand. This increases performance by about 7% on the standard benchmark suite. Introspection and debugging are unaffected as frame objects are always available when needed. Patch by Mark Shannon.
bpo-44584: The threading debug (
PYTHONTHREADDEBUG
environment variable) is deprecated in Python 3.10 and will be removed in Python 3.12. This feature requires a debug build of Python. Patch by Victor Stinner.bpo-43895: An obsolete internal cache of shared object file handles added in 1995 that attempted, but did not guarantee, that a .so would not be dlopen’ed twice to work around flaws in mid-1990s posix-ish operating systems has been removed from dynload_shlib.c.
bpo-44490:
typing
now searches for type parameters intypes.Union
objects.get_type_hints
will also properly resolve annotations with nestedtypes.Union
objects. Patch provided by Yurii Karabas.bpo-43950: Code objects can now provide the column information for instructions when available. This is levaraged during traceback printing to show the expressions responsible for errors.
Contributed by Pablo Galindo, Batuhan Taskaya and Ammar Askar as part of PEP 657.
bpo-44562: Remove uses of
PyObject_GC_Del()
in error path when initializingtypes.GenericAlias
.bpo-41486: Fix a memory consumption and copying performance regression in earlier 3.10 beta releases if someone used an output buffer larger than 4GiB with zlib.decompress on input data that expands that large.
bpo-43908: Heap types with the
Py_TPFLAGS_IMMUTABLETYPE
flag can now inherit the PEP 590 vectorcall protocol. Previously, this was only possible for static types. Patch by Erlend E. Aasland.bpo-44553: Implement GC methods for
types.Union
to break reference cycles and prevent memory leaks.bpo-44490: Add
__parameters__
attribute and__getitem__
operator totypes.Union
. Patch provided by Yurii Karabas.bpo-44523: Remove the pass-through for
hash()
ofweakref.proxy
objects to prevent unintended consequences when the original referred object dies while the proxy is part of a hashable object. Patch by Pablo Galindo.bpo-44483: Fix a crash in
types.Union
objects when creating a union of an object with bad__module__
field.bpo-44486: Modules will always have a dictionary, even when created by
types.ModuleType.__new__()
bpo-44472: Fix ltrace functionality when exceptions are raised. Patch by Pablo Galindo
bpo-12022: A
TypeError
is now raised instead of anAttributeError
inwith
andasync with
statements for objects which do not support the context manager or asynchronous context manager protocols correspondingly.bpo-44297: Make sure that the line number is set when entering a comprehension scope. Ensures that backtraces inclusing generator expressions show the correct line number.
bpo-44456: Improve the syntax error when mixing positional and keyword patterns. Patch by Pablo Galindo.
bpo-44409: Fix error location information for tokenizer errors raised on initialization of the tokenizer. Patch by Pablo Galindo.
bpo-44396: Fix a possible crash in the tokenizer when raising syntax errors for unclosed strings. Patch by Pablo Galindo.
bpo-44376: Exact integer exponentiation (like
i**2
orpow(i, 2)
) with a small exponent is much faster, due to reducing overhead in such cases.bpo-44313: Directly imported objects and modules (through import and from import statements) don’t generate
LOAD_METHOD
/CALL_METHOD
for directly accessed objects on their namespace. They now use the regularLOAD_ATTR
/CALL_FUNCTION
.bpo-44338: Implement adaptive specialization for LOAD_GLOBAL
Two specialized forms of LOAD_GLOBAL are added:
LOAD_GLOBAL_MODULE
LOAD_GLOBAL_BUILTIN
bpo-44368: Improve syntax errors for invalid “as” targets. Patch by Pablo Galindo
bpo-44349: Fix an edge case when displaying text from files with encoding in syntax errors. Patch by Pablo Galindo.
bpo-44337: Initial implementation of adaptive specialization of LOAD_ATTR
Four specialized forms of LOAD_ATTR are added:
LOAD_ATTR_SLOT
LOAD_ATTR_SPLIT_KEYS
LOAD_ATTR_WITH_HINT
LOAD_ATTR_MODULE
bpo-44335: Fix a regression when identifying incorrect characters in syntax errors. Patch by Pablo Galindo
bpo-43693: Computation of the offsets of cell variables is done in the compiler instead of at runtime. This reduces the overhead of handling cell and free variables, especially in the case where a variable is both an argument and cell variable.
bpo-44317: Improve tokenizer error with improved locations. Patch by Pablo Galindo.
bpo-44304: Fix a crash in the
sqlite3
module that happened when the garbage collector clearssqlite.Statement
objects. Patch by Pablo Galindobpo-44305: Improve error message for
try
blocks withoutexcept
orfinally
blocks. Patch by Pablo Galindo.bpo-43413: Constructors of subclasses of some builtin classes (e.g.
tuple
,list
,frozenset
) no longer accept arbitrary keyword arguments. [reverted in 3.11a4] Subclass ofset
can now define a__new__()
method with additional keyword parameters without overriding also__init__()
.bpo-43667: Improve Unicode support in non-UTF locales on Oracle Solaris. This issue does not affect other Solaris systems.
bpo-43693: A new opcode MAKE_CELL has been added that effectively moves some of the work done on function entry into the compiler and into the eval loop. In addition to creating the required cell objects, the new opcode converts relevant arguments (and other locals) to cell variables on function entry.
bpo-44232: Fix a regression in
type()
when a metaclass raises an exception. The C functiontype_new()
must properly report the exception when a metaclass constructor raises an exception and the winner class is not the metaclass. Patch by Victor Stinner.bpo-44201: Avoid side effects of checking for specialized syntax errors in the REPL that was causing it to ask for extra tokens after a syntax error had been detected. Patch by Pablo Galindo
bpo-43693:
PyCodeObject
gainedco_fastlocalnames
andco_fastlocalkinds
as the authoritative source of fast locals info. Marshaled code objects have changed accordingly.bpo-44184: Fix a crash at Python exit when a deallocator function removes the last strong reference to a heap type. Patch by Victor Stinner.
bpo-44187: Implement quickening in the interpreter. This offers no advantages as yet, but is an enabler of future optimizations. See PEP 659 for full explanation.
bpo-44180: The parser doesn’t report generic syntax errors that happen in a position further away that the one it reached in the first pass. Patch by Pablo Galindo
bpo-44168: Fix error message in the parser involving keyword arguments with invalid expressions. Patch by Pablo Galindo
bpo-44156: String caches in
compile.c
are now subinterpreter compatible.bpo-44143: Fixed a crash in the parser that manifest when raising tokenizer errors when an existing exception was present. Patch by Pablo Galindo.
bpo-44032: Move ‘fast’ locals and other variables from the frame object to a per-thread datastack.
bpo-44114: Fix incorrect dictkeys_reversed and dictitems_reversed function signatures in C code, which broke webassembly builds.
bpo-44110: Improve
str.__getitem__()
error messagebpo-26110: Add
CALL_METHOD_KW
opcode to speed up method calls with keyword arguments. Idea originated from PyPy. A side effect is executingCALL_METHOD
is now branchless in the evaluation loop.bpo-28307: Compiler now optimizes simple C-style formatting with literal format containing only format codes %s, %r and %a by converting them to f-string expressions.
bpo-43149: Correct the syntax error message regarding multiple exception types to not refer to “exception groups”. Patch by Pablo Galindo
bpo-43822: The parser will prioritize tokenizer errors over custom syntax errors when raising exceptions. Patch by Pablo Galindo.
bpo-40222: “Zero cost” exception handling.
Uses a lookup table to determine how to handle exceptions.
Removes SETUP_FINALLY and POP_TOP block instructions, eliminating the runtime overhead of try statements.
Reduces the size of the frame object by about 60%.
Patch by Mark Shannon
bpo-43918: Document the signature and
default
argument in the docstring of the newanext
builtin.bpo-43833: Emit a deprecation warning if the numeric literal is immediately followed by one of keywords: and, else, for, if, in, is, or. Raise a syntax error with more informative message if it is immediately followed by other keyword or identifier.
bpo-43879: Add native_thread_id to PyThreadState. Patch by Gabriele N. Tornetta.
bpo-43693: Compute cell offsets relative to locals in compiler. Allows the interpreter to treats locals and cells a single array, which is slightly more efficient. Also make the LOAD_CLOSURE opcode an alias for LOAD_FAST. Preserving LOAD_CLOSURE helps keep bytecode a bit more readable.
bpo-17792: More accurate error messages for access of unbound locals or free vars.
bpo-28146: Fix a confusing error message in
str.format()
.bpo-11105: When compiling
ast.AST
objects with recursive references throughcompile()
, the interpreter doesn’t crash anymore instead it raises aRecursionError
.bpo-39091: Fix crash when using passing a non-exception to a generator’s
throw()
method. Patch by Noah Oxerbpo-33346: Asynchronous comprehensions are now allowed inside comprehensions in asynchronous functions. Outer comprehensions implicitly become asynchronous.
Library¶
bpo-45371: Fix clang rpath issue in
distutils
. The UnixCCompiler now uses correct clang option to add a runtime library directory (rpath) to a shared library.bpo-45329: Fix freed memory access in
pyexpat.xmlparser
when building it with an installed expat library <= 2.2.0.bpo-41710: On Unix, if the
sem_clockwait()
function is available in the C library (glibc 2.30 and newer), thethreading.Lock.acquire()
method now uses the monotonic clock (time.CLOCK_MONOTONIC
) for the timeout, rather than using the system clock (time.CLOCK_REALTIME
), to not be affected by system clock changes. Patch by Victor Stinner.bpo-1596321: Fix the
threading._shutdown()
function when thethreading
module was imported first from a thread different than the main thread: no longer log an error at Python exit.bpo-45274: Fix a race condition in the
Thread.join()
method of thethreading
module. If the function is interrupted by a signal and the signal handler raises an exception, make sure that the thread remains in a consistent state to prevent a deadlock. Patch by Victor Stinner.bpo-21302: In Unix operating systems,
time.sleep()
now uses thenanosleep()
function, ifclock_nanosleep()
is not available butnanosleep()
is available.nanosleep()
allows to sleep with nanosecond precision.bpo-21302: On Windows,
time.sleep()
now uses a waitable timer which has a resolution of 100 nanoseconds (10-7 seconds). Previously, it had a resolution of 1 millisecond (10-3 seconds). Patch by Benjamin Szőke and Victor Stinner.bpo-45238: Fix
unittest.IsolatedAsyncioTestCase.debug()
: it runs now asynchronous methods and callbacks.bpo-36674:
unittest.TestCase.debug()
raises now aunittest.SkipTest
if the class or the test method are decorated with the skipping decorator.bpo-45235: Fix an issue where argparse would not preserve values in a provided namespace when using a subparser with defaults.
bpo-45183: Have zipimport.zipimporter.find_spec() not raise an exception when the underlying zip file has been deleted and the internal cache has been reset via invalidate_cache().
bpo-45234: Fixed a regression in
copyfile()
,copy()
,copy2()
raisingFileNotFoundError
when source is a directory, which should raiseIsADirectoryError
bpo-45228: Fix stack buffer overflow in parsing J1939 network address.
bpo-45225: use map function instead of genexpr in capwords.
bpo-42135: Fix typo:
importlib.find_loader
is really slated for removal in Python 3.12 not 3.10, like the others in PR 25169.Patch by Hugo van Kemenade.
bpo-20524: Improves error messages on
.format()
operation forstr
,float
,int
, andcomplex
. New format now shows the problematic pattern and the object type.bpo-45168: Change
dis.dis()
output to omit op arg values that cannot be resolved due toco_consts
,co_names
etc not being provided. Previously the oparg itself was repeated in the value field, which is not useful and can be confusing.bpo-21302: In Unix operating systems,
time.sleep()
now uses theclock_nanosleep()
function, if available, which allows to sleep for an interval specified with nanosecond precision.bpo-45173: Remove from the
configparser
module: theSafeConfigParser
class, thefilename
property of theParsingError
class, thereadfp()
method of theConfigParser
class, deprecated since Python 3.2.Patch by Hugo van Kemenade.
bpo-44987: Pure ASCII strings are now normalized in constant time by
unicodedata.normalize()
. Patch by Dong-hee Na.bpo-35474: Calling
mimetypes.guess_all_extensions()
withstrict=False
no longer affects the result of the following call withstrict=True
. Also, mutating the returned list no longer affects the global state.bpo-45166:
typing.get_type_hints()
now works withFinal
wrapped inForwardRef
.bpo-45162: Remove many old deprecated
unittest
features:“
fail*
” and “assert*
” aliases ofTestCase
methods.Broken from start
TestCase
methodassertDictContainsSubset()
.Ignored
<unittest.TestLoader.loadTestsFromModule> TestLoader.loadTestsFromModule()
parameter use_load_tests.Old alias
_TextTestResult
ofTextTestResult
.
bpo-38371: Remove the deprecated
split()
method of_tkinter.TkappType
. Patch by Erlend E. Aasland.bpo-20499: Improve the speed and accuracy of statistics.pvariance().
bpo-45132: Remove
__getitem__()
methods ofxml.dom.pulldom.DOMEventStream
,wsgiref.util.FileWrapper
andfileinput.FileInput
, deprecated since Python 3.9.Patch by Hugo van Kemenade.
bpo-45129: Due to significant security concerns, the reuse_address parameter of
asyncio.loop.create_datagram_endpoint()
, disabled in Python 3.9, is now entirely removed. This is because of the behavior of the socket optionSO_REUSEADDR
in UDP.Patch by Hugo van Kemenade.
bpo-45124: The
bdist_msi
command, deprecated in Python 3.9, is now removed.Use
bdist_wheel
(wheel packages) instead.Patch by Hugo van Kemenade.
bpo-30856:
unittest.TestResult
methodsaddFailure()
,addError()
,addSkip()
andaddSubTest()
are now called immediately after raising an exception in test or finishing a subtest. Previously they were called only after finishing the test clean up.bpo-45034: Changes how error is formatted for
struct.pack
with'H'
and'h'
modes and too large / small numbers. Now it shows the actual numeric limits, while previously it was showing arithmetic expressions.bpo-25894:
unittest
now always reports skipped and failed subtests separately: separate characters in default mode and separate lines in verbose mode. Also the test description is now output for errors in test method, class and module cleanups.bpo-45081: Fix issue when dataclasses that inherit from
typing.Protocol
subclasses have wrong__init__
. Patch provided by Yurii Karabas.bpo-45085: The
binhex
module, deprecated in Python 3.9, is now removed. The followingbinascii
functions, deprecated in Python 3.9, are now also removed:a2b_hqx()
,b2a_hqx()
;rlecode_hqx()
,rledecode_hqx()
.
The
binascii.crc_hqx()
function remains available.Patch by Victor Stinner.
bpo-40360: The
lib2to3
package is now deprecated and may not be able to parse Python 3.10 or newer. See the PEP 617 (New PEG parser for CPython). Patch by Victor Stinner.bpo-45075: Rename
traceback.StackSummary.format_frame()
totraceback.StackSummary.format_frame_summary()
. This method was added for 3.11 so it was not released yet.Updated code and docs to better distinguish frame and FrameSummary.
bpo-31299: Add option to completely drop frames from a traceback by returning
None
from aformat_frame()
override.bpo-41620:
run()
now always return aTestResult
instance. Previously it returnedNone
if the test class or method was decorated with a skipping decorator.bpo-45021: Fix a potential deadlock at shutdown of forked children when using
concurrent.futures
modulebpo-43913: Fix bugs in cleaning up classes and modules in
unittest
:Functions registered with
addModuleCleanup()
were not called unless the user definestearDownModule()
in their test module.Functions registered with
addClassCleanup()
were not called iftearDownClass
is set toNone
.Buffering in
TestResult
did not work with functions registered withaddClassCleanup()
andaddModuleCleanup()
.Errors in functions registered with
addClassCleanup()
andaddModuleCleanup()
were not handled correctly in buffered and debug modes.Errors in
setUpModule()
and functions registered withaddModuleCleanup()
were reported in wrong order.And several lesser bugs.
bpo-45030: Fix integer overflow in pickling and copying the range iterator.
bpo-45001: Made email date parsing more robust against malformed input, namely a whitespace-only
Date:
header. Patch by Wouter Bolsterlee.bpo-45010: Remove support of special method
__div__
inunittest.mock
. It is not used in Python 3.bpo-39218: Improve accuracy of variance calculations by using
x*x
instead ofx**2
.bpo-43613: Improve the speed of
gzip.compress()
andgzip.decompress()
by compressing and decompressing at once in memory instead of in a streamed fashion.bpo-37596: Ensure that
set
andfrozenset
objects are alwaysmarshalled
reproducibly.bpo-44019: A new function
operator.call
has been added, such thatoperator.call(obj, *args, **kwargs) == obj(*args, **kwargs)
.bpo-42255:
webbrowser.MacOSX
is deprecated and will be removed in Python 3.13. It is untested and undocumented and also not used by webbrowser itself. Patch by Dong-hee Na.bpo-44955: Method
stopTestRun()
is now always called in pair with methodstartTestRun()
forTestResult
objects implicitly created inrun()
. Previously it was not called for test methods and classes decorated with a skipping decorator.bpo-39039: tarfile.open raises
ReadError
when a zlib error occurs during file extraction.bpo-44935:
subprocess
on Solaris now also usesos.posix_spawn()
for better performance.bpo-44911:
IsolatedAsyncioTestCase
will no longer throw an exception while cancelling leaked tasks. Patch by Bar Harel.bpo-41322: Added
DeprecationWarning
for tests and async tests that return a value!=None (as this may indicate an improperly written test, for example a test written as a generator function).bpo-44524: Make exception message more useful when subclass from typing special form alias. Patch provided by Yurii Karabas.
bpo-38956:
argparse.BooleanOptionalAction
’s default value is no longer printed twice when used withargparse.ArgumentDefaultsHelpFormatter
.bpo-44860: Fix the
posix_user
scheme insysconfig
to not depend onsys.platlibdir
.bpo-44859: Improve error handling in
sqlite3
and raise more accurate exceptions.MemoryError
is now raised instead ofsqlite3.Warning
when memory is not enough for encoding a statement to UTF-8 inConnection.__call__()
andCursor.execute()
.UnicodEncodeError
is now raised instead ofsqlite3.Warning
when the statement contains surrogate characters inConnection.__call__()
andCursor.execute()
.TypeError
is now raised instead ofValueError
for non-string script argument inCursor.executescript()
.ValueError
is now raised for script containing the null character instead of truncating it inCursor.executescript()
.Correctly handle exceptions raised when getting boolean value of the result of the progress handler.
Add many tests covering different corner cases.
bpo-44581: Upgrade bundled pip to 21.2.3 and setuptools to 57.4.0
bpo-44849: Fix the
os.set_inheritable()
function on FreeBSD 14 for file descriptor opened with theO_PATH
flag: ignore theEBADF
error onioctl()
, fallback on thefcntl()
implementation. Patch by Victor Stinner.bpo-44605: The @functools.total_ordering() decorator now works with metaclasses.
bpo-44524: Fixed an issue wherein the
__name__
and__qualname__
attributes of subscribed specialforms could beNone
.bpo-44839:
MemoryError
raised in user-defined functions will now produce aMemoryError
insqlite3
.OverflowError
will now be converted toDataError
. PreviouslyOperationalError
was produced in these cases.bpo-44822:
sqlite3
user-defined functions and aggregators returningstrings
with embedded NUL characters are no longer truncated. Patch by Erlend E. Aasland.bpo-44801: Ensure that the
ParamSpec
variable in Callable can only be substituted with a parameters expression (a list of types, an ellipsis, ParamSpec or Concatenate).bpo-44806: Non-protocol subclasses of
typing.Protocol
ignore now the__init__
method inherited from protocol base classes.bpo-27275:
collections.OrderedDict.popitem()
andcollections.OrderedDict.pop()
no longer call__getitem__
and__delitem__
methods of the OrderedDict subclasses.bpo-44793: Fix checking the number of arguments when subscribe a generic type with
ParamSpec
parameter.bpo-44784: In importlib.metadata tests, override warnings behavior under expected DeprecationWarnings (importlib_metadata 4.6.3).
bpo-44667: The
tokenize.tokenize()
doesn’t incorrectly generate aNEWLINE
token if the source doesn’t end with a new line character but the last line is a comment, as the function is already generating aNL
token. Patch by Pablo Galindobpo-44771: Added
importlib.simple
module implementing adapters from a low-level resources reader interface to aTraversableResources
interface. Legacy API (path
,contents
, …) is now supported entirely by the.files()
API with a compatibility shim supplied for resource loaders without that functionality. Feature parity withimportlib_resources
5.2.bpo-44752:
rcompleter
does not callgetattr()
onproperty
objects to avoid the side-effect of evaluating the corresponding method.bpo-44747: Refactor usage of
sys._getframe
intyping
module. Patch provided by Yurii Karabas.bpo-42378: Fixes the issue with log file being overwritten when
logging.FileHandler
is used inatexit
with filemode set to'w'
. Note this will cause the message in atexit not being logged if the log stream is already closed due to shutdown of logging.bpo-44720:
weakref.proxy
objects referencing non-iterators now raiseTypeError
rather than dereferencing the nulltp_iternext
slot and crashing.bpo-44704: The implementation of
collections.abc.Set._hash()
now matches that offrozenset.__hash__()
.bpo-44666: Fixed issue in
compileall.compile_file()
whensys.stdout
is redirected. Patch by Stefan Hölzl.bpo-44688:
sqlite3.Connection.create_collation()
now accepts non-ASCII collation names. Patch by Erlend E. Aasland.bpo-44690: Adopt binacii.a2b_base64’s strict mode in base64.b64decode.
bpo-42854: Fixed a bug in the
_ssl
module that was throwingOverflowError
when using_ssl._SSLSocket.write()
and_ssl._SSLSocket.read()
for a big value of thelen
parameter. Patch by Pablo Galindobpo-44686: Replace
unittest.mock._importer
withpkgutil.resolve_name
.bpo-44353: Make
NewType.__call__
faster by implementing it in C. Patch provided by Yurii Karabas.bpo-44682: Change the
pdb
commands directive to disallow setting commands for an invalid breakpoint and to display an appropriate error.bpo-44353: Refactor
typing.NewType
from function into callable class. Patch provided by Yurii Karabas.bpo-44678: Added a separate error message for discontinuous padding in binascii.a2b_base64 strict mode.
bpo-44524: Add missing
__name__
and__qualname__
attributes totyping
module classes. Patch provided by Yurii Karabas.bpo-40897: Give priority to using the current class constructor in
inspect.signature()
. Patch by Weipeng Hong.bpo-44638: Add a reference to the zipp project and hint as to how to use it.
bpo-44648: Fixed wrong error being thrown by
inspect.getsource()
when examining a class in the interactive session. Instead ofTypeError
, it should beOSError
with appropriate error message.bpo-44608: Fix memory leak in
_tkinter._flatten()
if it is called with a sequence or set, but not list or tuple.bpo-44594: Fix an edge case of
ExitStack
andAsyncExitStack
exception chaining. They will now matchwith
block behavior when__context__
is explicitly set toNone
when the exception is in flight.bpo-42799: In
fnmatch
, the cache size for compiled regex patterns (functools.lru_cache()
) was bumped up from 256 to 32768, affecting functions:fnmatch.fnmatch()
,fnmatch.fnmatchcase()
,fnmatch.filter()
.bpo-41928: Update
shutil.copyfile()
to raiseFileNotFoundError
instead of confusingIsADirectoryError
when a path ending with aos.path.sep
does not exist;shutil.copy()
andshutil.copy2()
are also affected.bpo-44569: Added the
StackSummary.format_frame()
function intraceback
. This allows users to customize the way individual lines are formatted in tracebacks without re-implementing logic to handle recursive tracebacks.bpo-44566: handle StopIteration subclass raised from @contextlib.contextmanager generator
bpo-44558: Make the implementation consistency of
indexOf()
between C and Python versions. Patch by Dong-hee Na.bpo-41249: Fixes
TypedDict
to work withtyping.get_type_hints()
and postponed evaluation of annotations across modules.bpo-44554: Refactor argument processing in
pdb.main()
to simplify detection of errors in input loading and clarify behavior around module or script invocation.bpo-34798: Break up paragraph about
pprint.PrettyPrinter
construction parameters to make it easier to read.bpo-44539: Added support for recognizing JPEG files without JFIF or Exif markers.
bpo-44461: Fix bug with
pdb
’s handling of import error due to a package which does not have a__main__
modulebpo-43625: Fix a bug in the detection of CSV file headers by
csv.Sniffer.has_header()
and improve documentation of same.bpo-44516: Update vendored pip to 21.1.3
bpo-42892: Fixed an exception thrown while parsing a malformed multipart email by
email.message.EmailMessage
.bpo-44468:
typing.get_type_hints()
now finds annotations in classes and base classes with unexpected__module__
. Previously, it skipped those MRO elements.bpo-44491: Allow clearing the
sqlite3
authorizer callback by passingNone
toset_authorizer()
. Patch by Erlend E. Aasland.bpo-43977: Set the proper
Py_TPFLAGS_MAPPING
andPy_TPFLAGS_SEQUENCE
flags for subclasses created before a parent has been registered as acollections.abc.Mapping
orcollections.abc.Sequence
.bpo-44482: Fix very unlikely resource leak in
glob
in alternate Python implementations.bpo-44466: The
faulthandler
module now detects if a fatal error occurs during a garbage collector collection. Patch by Victor Stinner.bpo-44471: A
TypeError
is now raised instead of anAttributeError
incontextlib.ExitStack.enter_context()
andcontextlib.AsyncExitStack.enter_async_context()
for objects which do not support the context manager or asynchronous context manager protocols correspondingly.bpo-44404:
tkinter
’safter()
method now supports callables without the__name__
attribute.bpo-41546: Make
pprint
(like the builtinprint
) not attempt to write tostdout
when it isNone
.bpo-44458:
BUFFER_BLOCK_SIZE
is now declared static, to avoid linking collisions when bz2, lmza or zlib are statically linked.bpo-44464: Remove exception for flake8 in deprecated importlib.metadata interfaces. Sync with importlib_metadata 4.6.
bpo-44446: Take into account that
lineno
might beNone
intraceback.FrameSummary
.bpo-44439: Fix in
bz2.BZ2File.write()
/lzma.LZMAFile.write()
methods, when the input data is an object that supports the buffer protocol, the file length may be wrong.bpo-44434: _thread.start_new_thread() no longer calls PyThread_exit_thread() explicitly at the thread exit, the call was redundant. On Linux with the glibc, pthread_exit() aborts the whole process if dlopen() fails to open libgcc_s.so file (ex: EMFILE error). Patch by Victor Stinner.
bpo-42972: The _thread.RLock type now fully implement the GC protocol: add a traverse function and the
Py_TPFLAGS_HAVE_GC
flag. Patch by Victor Stinner.bpo-44422: The
threading.enumerate()
function now uses a reentrant lock to prevent a hang on reentrant call. Patch by Victor Stinner.bpo-38291: Importing typing.io or typing.re now prints a
DeprecationWarning
.bpo-37880: argparse actions store_const and append_const each receive a default value of None when the
const
kwarg is not provided. Previously, this raised aTypeError
.bpo-44389: Fix deprecation of
ssl.OP_NO_TLSv1_3
bpo-27827:
pathlib.PureWindowsPath.is_reserved()
now identifies a greater range of reserved filenames, including those with trailing spaces or colons.bpo-44395: Fix
as_string()
to pass unixfrom properly. Patch by Dong-hee Na.bpo-34266: Handle exceptions from parsing the arg of
pdb
’s run/restart command.bpo-44362: Improve
ssl
module’s deprecation messages, error reporting, and documentation for deprecations.bpo-44342: [Enum] Change pickling from by-value to by-name.
bpo-44356: [Enum] Allow multiple data-type mixins if they are all the same.
bpo-44351: Restore back
parse_makefile()
indistutils.sysconfig
because it behaves differently than the similar implementation insysconfig
.bpo-35800:
smtpd.MailmanProxy
is now removed as it is unusable without an external module,mailman
. Patch by Dong-hee Na.bpo-44357: Added a function that returns cube root of the given number
math.cbrt()
bpo-44339: Change
math.pow(±0.0, -math.inf)
to returninf
instead of raisingValueError
. This brings the special-case handling ofmath.pow
into compliance with the IEEE 754 standard.bpo-44242: Remove missing flag check from Enum creation and move into a
verify
decorator.bpo-44246: In
importlib.metadata
, restore compatibility in the result fromDistribution.entry_points
(EntryPoints
) to honor expectations in older implementations and issuing deprecation warnings for these cases: A.EntryPoints
objects are once again mutable, allowing forsort()
and other list-based mutation operations. Avoid deprecation warnings by casting to a mutable sequence (e.g.list(dist.entry_points).sort()
). B.EntryPoints
results once again allow for access by index. To avoid deprecation warnings, cast the result to a Sequence first (e.g.tuple(dist.entry_points)[0]
).bpo-44246: In importlib.metadata.entry_points, de-duplication of distributions no longer requires loading the full metadata for PathDistribution objects, improving entry point loading performance by ~10x.
bpo-43858: Added a function that returns a copy of a dict of logging levels:
logging.getLevelNamesMapping()
bpo-44260: The
random.Random
constructor no longer reads system entropy without need.bpo-44254: On Mac, give turtledemo button text a color that works on both light or dark background. Programmers cannot control the latter.
bpo-44258: Support PEP 515 for Fraction’s initialization from string.
bpo-44235: Remove deprecated functions in the
gettext
. Patch by Dong-hee Na.bpo-38693: Prefer f-strings to
.format
in importlib.resources.bpo-33693: Importlib.metadata now prefers f-strings to .format.
bpo-44241: Incorporate minor tweaks from importlib_metadata 4.1: SimplePath protocol, support for Metadata 2.2.
bpo-43216: Remove the
@asyncio.coroutine
decorator enabling legacy generator-based coroutines to be compatible with async/await code; removeasyncio.coroutines.CoroWrapper
used for wrapping legacy coroutine objects in the debug mode. The decorator has been deprecated since Python 3.8 and the removal was initially scheduled for Python 3.10. Patch by Illia Volochii.bpo-44210: Make importlib.metadata._meta.PackageMetadata public.
bpo-43643: Declare readers.MultiplexedPath.name as a property per the spec.
bpo-27334: The
sqlite3
context manager now performs a rollback (thus releasing the database lock) if commit failed. Patch by Luca Citi and Erlend E. Aasland.bpo-4928: Documented existing behavior on POSIX: NamedTemporaryFiles are not deleted when creating process is killed with SIGKILL
bpo-44154: Optimize
fractions.Fraction
pickling for large components.bpo-33433: For IPv4 mapped IPv6 addresses (RFC 4291 Section 2.5.5.2), the
ipaddress.IPv6Address.is_private
check is deferred to the mapped IPv4 address. This solves a bug where public mapped IPv4 addresses were considered private by the IPv6 check.bpo-44150: Add optional weights argument to statistics.fmean().
bpo-44142:
ast.unparse()
will now drop the redundant parentheses when tuples used as assignment targets (e.g in for loops).bpo-44145:
hmac
computations were not releasing the GIL while calling the OpenSSLHMAC_Update
C API (a new feature in 3.9). This unintentionally prevented parallel computation as otherhashlib
algorithms support.bpo-44095:
zipfile.Path
now supportszipfile.Path.stem
,zipfile.Path.suffixes
, andzipfile.Path.suffix
attributes.bpo-44077: It’s now possible to receive the type of service (ToS), a.k.a. differentiated services (DS), a.k.a. differentiated services code point (DSCP) and explicit congestion notification (ECN) IP header fields with
socket.IP_RECVTOS
.bpo-37788: Fix a reference leak when a Thread object is never joined.
bpo-38908: Subclasses of
typing.Protocol
which only have data variables declared will now raise aTypeError
when checked withisinstance
unless they are decorated withruntime_checkable()
. Previously, these checks passed silently. Patch provided by Yurii Karabas.bpo-44098:
typing.ParamSpec
will no longer be found in the__parameters__
of mosttyping
generics except in valid use locations specified by PEP 612. This prevents incorrect usage liketyping.List[P][int]
. This change means incorrect usage which may have passed silently in 3.10 beta 1 and earlier will now error.bpo-44089: Allow subclassing
csv.Error
in 3.10 (it was allowed in 3.9 and earlier but was disallowed in early versions of 3.10).bpo-44081:
ast.unparse()
now doesn’t use redundant spaces to separatelambda
and the:
if there are no parameters.bpo-44061: Fix regression in previous release when calling
pkgutil.iter_modules()
with a list ofpathlib.Path
objectsbpo-44059: Register the SerenityOS Browser in the
webbrowser
module.bpo-36515: The
hashlib
module no longer does unaligned memory accesses when compiled for ARM platforms.bpo-40465: Remove random module features deprecated in Python 3.9.
bpo-44018: random.seed() no longer mutates bytearray inputs.
bpo-38352: Add
IO
,BinaryIO
,TextIO
,Match
, andPattern
totyping.__all__
. Patch by Jelle Zijlstra.bpo-44002:
urllib.parse
now usesfunctool.lru_cache()
for its internal URL splitting and quoting caches instead of rolling its own like its the ’90s.The undocumented internal
urllib.parse
Quoted
class API is now deprecated, for removal in 3.14.bpo-43972: When
http.server.SimpleHTTPRequestHandler
sends a301 (Moved Permanently)
for a directory path not ending with/
, add aContent-Length: 0
header. This improves the behavior for certain clients.bpo-28528: Fix a bug in
pdb
wherecheckline()
raisesAttributeError
if it is called afterreset()
.bpo-43853: Improved string handling for
sqlite3
user-defined functions and aggregates:It is now possible to pass strings with embedded null characters to UDFs
Conversion failures now correctly raise
MemoryError
Patch by Erlend E. Aasland.
bpo-43666: AIX:
Lib/_aix_support.get_platform()
may fail in an AIX WPAR. The fileset bos.rte appears to have a builddate in both LPAR and WPAR so this fileset is queried rather than bos.mp64. To prevent a similar situation (no builddate in ODM) a value (9988) sufficient for completing a build is provided. Patch by M Felt.bpo-43650: Fix
MemoryError
inshutil.unpack_archive()
which fails insideshutil._unpack_zipfile()
on large files. Patch by Igor Bolshakov.bpo-43612:
zlib.compress()
now accepts a wbits parameter which allows users to compress data as a raw deflate block without zlib headers and trailers in one go. Previously this required instantiating azlib.compressobj
. It also provides a faster alternative togzip.compress
when wbits=31 is used.bpo-43392:
importlib._bootstrap._find_and_load()
now implements a two-step check to avoid locking when modules have been already imported and are ready. This improves performance of repeated calls toimportlib.import_module()
andimportlib.__import__()
.bpo-43318: Fix a bug where
pdb
does not always echo cleared breakpoints.bpo-43234: Prohibit passing non-
concurrent.futures.ThreadPoolExecutor
executors toloop.set_default_executor()
following a deprecation in Python 3.8. Patch by Illia Volochii.bpo-43232: Prohibit previously deprecated potentially disruptive operations on
asyncio.trsock.TransportSocket
. Patch by Illia Volochii.bpo-30077: Added support for Apple’s aifc/sowt pseudo-compression
bpo-42971: Add definition of
errno.EQFULL
for platforms that define this constant (such as macOS).bpo-43086: Added a new optional
strict_mode
parameter to binascii.a2b_base64. Whenscrict_mode
is set toTrue
, the a2b_base64 function will accept only valid base64 content. More details about what “valid base64 content” is, can be found in the function’s documentation.bpo-43024: Improve the help signature of
traceback.print_exception()
,traceback.format_exception()
andtraceback.format_exception_only()
.bpo-33809: Add the
traceback.TracebackException.print()
method which prints the formatted exception information.bpo-42862:
sqlite3
now utilizesfunctools.lru_cache()
to implement the connection statement cache. As a small optimisation, the default statement cache size has been increased from 100 to 128. Patch by Erlend E. Aasland.bpo-41818: Soumendra Ganguly: add termios.tcgetwinsize(), termios.tcsetwinsize().
bpo-40497:
subprocess.check_output()
now raisesValueError
when the invalid keyword argument check is passed by user code. Previously such use would fail later with aTypeError
. Patch by Rémi Lapeyre.bpo-37449:
ensurepip
now usesimportlib.resources.files()
traversable APIsbpo-40956: Use Argument Clinic in
sqlite3
. Patches by Erlend E. Aasland.bpo-41730:
DeprecationWarning
is now raised when importingtkinter.tix
, which has been deprecated in documentation since Python 3.6.bpo-20684: Remove unused
_signature_get_bound_param
function frominspect
- by Anthony Sottile.bpo-41402: Fix
email.message.EmailMessage.set_content()
when called with binary data and7bit
content transfer encoding.bpo-32695: The compresslevel and preset keyword arguments of
tarfile.open()
are now both documented and tested.bpo-41137: Use utf-8 encoding while reading .pdbrc files. Patch by Srinivas Reddy Thatiparthy
bpo-24391: Improved reprs of
threading
synchronization objects:Semaphore
,BoundedSemaphore
,Event
andBarrier
.bpo-5846: Deprecated the following
unittest
functions, scheduled for removal in Python 3.13:findTestCases()
makeSuite()
getTestCaseNames()
Use
TestLoader
methods instead:Patch by Erlend E. Aasland.
bpo-40563: Support pathlike objects on dbm/shelve. Patch by Hakan Çelik and Henry-Joseph Audéoud.
bpo-34990: Fixed a Y2k38 bug in the compileall module where it would fail to compile files with a modification time after the year 2038.
bpo-39549: Whereas the code for reprlib.Repr had previously used a hardcoded string value of ‘…’, this PR updates it to use of a “fillvalue” attribute, whose value defaults to ‘…’ and can be reset in either individual reprlib.Repr instances or in subclasses thereof.
bpo-37022:
pdb
now displays exceptions fromrepr()
with itsp
andpp
commands.bpo-38840: Fix
test___all__
on platforms lacking a shared memory implementation.bpo-39359: Add one missing check that the password is a bytes object for an encrypted zipfile.
bpo-38741:
configparser
: using ‘]’ inside a section header will no longer cut the section name short at the ‘]’bpo-38415: Added missing behavior to
contextlib.asynccontextmanager()
to matchcontextlib.contextmanager()
so decorated functions can themselves be decorators.bpo-30256: Pass multiprocessing BaseProxy argument
manager_owned
through AutoProxy.bpo-27513:
email.utils.getaddresses()
now acceptsemail.header.Header
objects along with string values. Patch by Zackery Spytz.bpo-16379: Add SQLite error code and name to
sqlite3
exceptions. Patch by Aviv Palivoda, Daniel Shahaf, and Erlend E. Aasland.bpo-26228: pty.spawn no longer hangs on FreeBSD, macOS, and Solaris.
bpo-33349: lib2to3 now recognizes async generators everywhere.
bpo-29298: Fix
TypeError
when required subparsers withoutdest
do not receive arguments. Patch by Anthony Sottile.
Documentation¶
bpo-45216: Remove extra documentation listing methods in
difflib
. It was rendering twice in pydoc and was outdated in some places.bpo-45024:
collections.abc
documentation has been expanded to explicitly cover how instance and subclass checks work, with additional doctest examples and an exhaustive list of ABCs which test membership purely by presence of the right special methods. Patch by Raymond Hettinger.bpo-44957: Promote PEP 604 union syntax by using it where possible. Also, mention
X | Y
more prominently in section aboutUnion
and mentionX | None
at all in section aboutOptional
.bpo-16580: Added code equivalents for the
int.to_bytes()
andint.from_bytes()
methods, as well as tests ensuring that these code equivalents are valid.bpo-44903: Removed the othergui.rst file, any references to it, and the list of GUI frameworks in the FAQ. In their place I’ve added links to the Python Wiki
page on GUI frameworks
.bpo-33479: Tkinter documentation has been greatly expanded with new “Architecture” and “Threading model” sections.
bpo-36700:
base64
RFC references were updated to point to RFC 4648; a section was added to point users to the new “security considerations” section of the RFC.bpo-44740: Replaced occurrences of uppercase “Web” and “Internet” with lowercase versions per the 2016 revised Associated Press Style Book.
bpo-44693: Update the definition of __future__ in the glossary by replacing the confusing word “pseudo-module” with a more accurate description.
bpo-35183: Add typical examples to os.path.splitext docs
bpo-30511: Clarify that
shutil.make_archive()
is not thread-safe due to reliance on changing the current working directory.bpo-44561: Update of three expired hyperlinks in Doc/distributing/index.rst: “Project structure”, “Building and packaging the project”, and “Uploading the project to the Python Packaging Index”.
bpo-44651: Delete entry “coercion” in Doc/glossary.rst for its outdated definition.
bpo-42958: Updated the docstring and docs of
filecmp.cmp()
to be more accurate and less confusing especially in respect to shallow arg.bpo-44631: Refactored the
repr()
code of the_Environ
(os module).bpo-44613: importlib.metadata is no longer provisional.
bpo-44558: Match the docstring and python implementation of
countOf()
to the behavior of its c implementation.bpo-44544: List all kwargs for
textwrap.wrap()
,textwrap.fill()
, andtextwrap.shorten()
. Now, there are nav links to attributes ofTextWrap
, which makes navigation much easier while minimizing duplication in the documentation.bpo-38062: Clarify that atexit uses equality comparisons internally.
bpo-40620: Convert examples in tutorial controlflow.rst section 4.3 to be interpreter-demo style.
bpo-43066: Added a warning to
zipfile
docs: filename arg with a leading slash may cause archive to be un-openable on Windows systems.bpo-39452: Rewrote
Doc/library/__main__.rst
. Broadened scope of the document to explicitly discuss and differentiate between__main__.py
in packages versus the__name__ == '__main__'
expression (and the idioms that surround it).bpo-13814: In the Design FAQ, answer “Why don’t generators support the with statement?”
bpo-27752: Documentation of csv.Dialect is more descriptive.
bpo-44453: Fix documentation for the return type of
sysconfig.get_path()
.bpo-44392: Added a new section in the C API documentation for types used in type hinting. Documented
Py_GenericAlias
andPy_GenericAliasType
.bpo-38291: Mark
typing.io
andtyping.re
as deprecated since Python 3.8 in the documentation. They were never properly supported by type checkers.bpo-44322: Document that SyntaxError args have a details tuple and that details are adjusted for errors in f-string field replacement expressions.
bpo-42392: Document the deprecation and removal of the
loop
parameter for many functions and classes inasyncio
.bpo-44195: Corrected references to
TraversableResources
in docs. There is noTraversableReader
.bpo-41963: Document that
ConfigParser
strips off comments when reading configuration files.bpo-44072: Correct where in the numeric ABC hierarchy
**
support is added, i.e., in numbers.Complex, not numbers.Integral.bpo-43558: Add the remark to
dataclasses
documentation that the__init__()
of any base class has to be called in__post_init__()
, along with a code example.bpo-44025: Clarify when ‘_’ in match statements is a keyword, and when not.
bpo-41706: Fix docs about how methods like
__add__
are invoked when evaluating operator expressions.bpo-41621: Document that
collections.defaultdict
parameterdefault_factory
defaults to None and is positional-only.bpo-41576: document BaseException in favor of bare except
bpo-21760: The description for __file__ fixed. Patch by Furkan Onder
bpo-39498: Add a “Security Considerations” index which links to standard library modules that have explicitly documented security considerations.
bpo-33479: Remove the unqualified claim that tkinter is threadsafe. It has not been true for several years and likely never was. An explanation of what is true may be added later, after more discussion, and possibly after patching _tkinter.c,
Tests¶
bpo-40173: Fix
test.support.import_helper.import_fresh_module()
.bpo-45280: Add a test case for empty
typing.NamedTuple
.bpo-45269: Cover case when invalid
markers
type is supplied toc_make_encoder
.bpo-45128: Fix
test_multiprocessing_fork
failure due totest_logging
andsys.modules
manipulation.bpo-45209: Fix
UserWarning: resource_tracker
warning in_test_multiprocessing._TestSharedMemory.test_shared_memory_cleaned_after_process_termination
bpo-45185: Enables
TestEnumerations
test cases intest_ssl
suite.bpo-45195: Fix test_readline.test_nonascii(): sometimes, the newline character is not written at the end, so don’t expect it in the output. Patch by Victor Stinner.
bpo-45156: Fixes infinite loop on
unittest.mock.seal()
of mocks created bycreate_autospec()
.bpo-45125: Improves pickling tests and docs of
SharedMemory
andSharableList
objects.bpo-44860: Update
test_sysconfig.test_user_similar()
for the posix_user scheme:platlib
doesn’t usesys.platlibdir
. Patch by Victor Stinner.bpo-45052:
WithProcessesTestSharedMemory.test_shared_memory_basics
test was ignored, becauseself.assertEqual(sms.size, sms2.size)
line was failing. It is now removed and test is unskipped.The main motivation for this line to be removed from the test is that the
size
ofSharedMemory
is not ever guaranteed to be the same. It is decided by the platform.bpo-44895: libregrtest now clears the type cache later to reduce the risk of false alarm when checking for reference leaks. Previously, the type cache was cleared too early and libregrtest raised a false alarm about reference leaks under very specific conditions. Patch by Irit Katriel and Victor Stinner.
bpo-45042: Fixes that test classes decorated with
@hashlib_helper.requires_hashdigest
were skipped all the time.bpo-25130: Add calls of
gc.collect()
in tests to support PyPy.bpo-45011: Made tests relying on the
_asyncio
C extension module optional to allow running on alternative Python implementations. Patch by Serhiy Storchaka.bpo-44949: Fix auto history tests of test_readline: sometimes, the newline character is not written at the end, so don’t expect it in the output.
bpo-44891: Tests were added to clarify
id()
is preserved whenobj * 1
is used onstr
andbytes
objects. Patch by Nikita Sobolev.bpo-44852: Add ability to wholesale silence DeprecationWarnings while running the regression test suite.
bpo-40928: Notify users running test_decimal regression tests on macOS of potential harmless “malloc can’t allocate region” messages spewed by test_decimal.
bpo-44734: Fixed floating point precision issue in turtle tests.
bpo-44708: Regression tests, when run with -w, are now re-running only the affected test methods instead of re-running the entire test file.
bpo-42095: Added interop tests for Apple plists: generate plist files with Python plistlib and parse with Apple plutil; and the other way round.
bpo-44647: Added a permanent Unicode-valued environment variable to regression tests to ensure they handle this use case in the future. If your test environment breaks because of that, report a bug to us, and temporarily set PYTHONREGRTEST_UNICODE_GUARD=0 in your test environment.
bpo-44515: Adjust recently added contextlib tests to avoid assuming the use of a refcounted GC
bpo-44287: Fix asyncio test_popen() of test_windows_utils by using a longer timeout. Use military grade battle-tested
test.support.SHORT_TIMEOUT
timeout rather than a hardcoded timeout of 10 seconds: it’s 30 seconds by default, but it is made longer on slow buildbots. Patch by Victor Stinner.bpo-44451: Reset
DeprecationWarning
filters intest.test_importlib.test_metadata_api.APITests.test_entry_points_by_index
to avoidStopIteration
error ifDeprecationWarnings
are ignored.bpo-44363: Account for address sanitizer in test_capi. test_capi now passes when run GCC address sanitizer.
bpo-44364: Add non integral tests for
math.sqrt()
function.bpo-43921: Fix test_ssl.test_wrong_cert_tls13(): use
suppress_ragged_eofs=False
, sinceread()
can raisessl.SSLEOFError
on Windows. Patch by Victor Stinner.bpo-43921: Fix test_pha_required_nocert() of test_ssl: catch two more EOF cases (when the
recv()
method returns an empty string). Patch by Victor Stinner.bpo-44131: Add test_frozenmain to test_embed to test the
Py_FrozenMain()
C function. Patch by Victor Stinner.bpo-31904: Ignore error string case in test_file_not_exists().
bpo-42083: Add test to check that
PyStructSequence_NewType
accepts aPyStructSequence_Desc
withdoc
field set toNULL
.bpo-35753: Fix crash in doctest when doctest parses modules that include unwrappable functions by skipping those functions.
bpo-30256: Add test for nested queues when using
multiprocessing
shared objectsAutoProxy[Queue]
insideListProxy
andDictProxy
Build¶
bpo-45220: Avoid building with the Windows 11 SDK previews automatically. This may be overridden by setting the
DefaultWindowsSDKVersion
environment variable before building.bpo-45020: Freeze stdlib modules that are imported during startup. This provides significant performance improvements to startup. If necessary, use the previously added “-X frozen_modules=off” commandline option to force importing the source modules.
bpo-45188: Windows builds now regenerate frozen modules as the first part of the build. Previously the regeneration was later in the build, which would require it to be restarted if any modules had changed.
bpo-45163: Fixes Haiku platform build.
bpo-45067: The ncurses function extended_color_content was introduced in 2017
(https://invisible-island.net/ncurses/NEWS.html#index-t20170401). The
ncurses-devel package in CentOS 7 had a older version ncurses resulted in compilation error. For compiling ncurses with extended color support, we verify the version of the ncurses library >= 20170401.
bpo-45019: Generate lines in relevant files for frozen modules. Up until now each of the files had to be edited manually. This change makes it easier to add to and modify the frozen modules.
bpo-44340: Add support for building with clang thin lto via –with-lto=thin/full. Patch by Dong-hee Na and Brett Holman.
bpo-44535: Enable building using a Visual Studio 2022 install on Windows.
bpo-43298: Improved error message when building without a Windows SDK installed.
bpo-44381: The Windows build now accepts
EnableControlFlowGuard
set toguard
to enable CFG.bpo-41282: Fix broken
make install
that caused standard library extension modules to be unnecessarily and incorrectly rebuilt during the install phase of cpython.
Windows¶
bpo-45375: Fixes an assertion failure due to searching for the standard library in unnormalised paths.
bpo-45022: Update Windows release to include libffi 3.4.2
bpo-45007: Update to OpenSSL 1.1.1l in Windows build
bpo-44848: Upgrade Windows installer to use SQLite 3.36.0.
bpo-44572: Avoid consuming standard input in the
platform
modulebpo-44582: Accelerate speed of
mimetypes
initialization using a native implementation of the registry scan.bpo-41299: Fix 16 milliseconds jitter when using timeouts in
threading
, such as withthreading.Lock.acquire()
orthreading.Condition.wait()
.bpo-42686: Build
sqlite3
with math functions enabled. Patch by Erlend E. Aasland.bpo-40263: This is a follow-on bug from https://bugs.python.org/issue26903. Once that is applied we run into an off-by-one assertion problem. The assert was not correct.
macOS¶
bpo-45007: Update macOS installer builds to use OpenSSL 1.1.1l.
bpo-34602: When building CPython on macOS with
./configure --with-undefined-behavior-sanitizer --with-pydebug
, the stack size is now quadrupled to allow for the entire test suite to pass.bpo-44848: Update macOS installer to use SQLite 3.36.0.
bpo-44689:
ctypes.util.find_library()
now works correctly on macOS 11 Big Sur even if Python is built on an older version of macOS. Previously, when built on older macOS systems,find_library
was not able to find macOS system libraries when running on Big Sur due to changes in how system libraries are stored.bpo-41972: The framework build’s user header path in sysconfig is changed to add a ‘pythonX.Y’ component to match distutils’s behavior.
bpo-43109: Allow –with-lto configure option to work with Apple-supplied Xcode or Command Line Tools.
bpo-34932: Add socket.TCP_KEEPALIVE support for macOS. Patch by Shane Harvey.
IDLE¶
bpo-45296: On Windows, change exit/quit message to suggest Ctrl-D, which works, instead of <Ctrl-Z Return>, which does not work in IDLE.
bpo-45193: Make completion boxes appear on Ubuntu again.
bpo-40128: Mostly fix completions on macOS when not using tcl/tk 8.6.11 (as with 3.9). The added update_idletask call should be harmless and possibly helpful otherwise.
bpo-33962: Move the indent space setting from the Font tab to the new Windows tab. Patch by Mark Roseman and Terry Jan Reedy.
bpo-40468: Split the settings dialog General tab into Windows and Shell/ED tabs. Move help sources, which extend the Help menu, to the Extensions tab. Make space for new options and shorten the dialog. The latter makes the dialog better fit small screens.
bpo-41611: Avoid uncaught exceptions in
AutoCompleteWindow.winconfig_event()
.bpo-41611: Fix IDLE sometimes freezing upon tab-completion on macOS.
bpo-44010: Highlight the new match statement’s soft keywords:
match
,case
, and_
. However, this highlighting is not perfect and will be incorrect in some rare cases, including some_
-s incase
patterns.bpo-44026: Include interpreter’s typo fix suggestions in message line for NameErrors and AttributeErrors. Patch by E. Paine.
Tools/Demos¶
bpo-44786: Fix a warning in regular expression in the c-analyzer script.
bpo-44967: pydoc now returns a non-zero status code when a module cannot be found.
bpo-44978: Allow the Argument Clinic tool to handle
__complex__
special methods.bpo-43425: Removed the ‘test2to3’ demo project that demonstrated using lib2to3 to support Python 2.x and Python 3.x from a single source in a distutils package. Patch by Dong-hee Na
bpo-44074: Make patchcheck automatically detect the correct base branch name (previously it was hardcoded to ‘master’)
bpo-20291: Added support for variadic positional parameters in Argument Clinic.
C API¶
bpo-41710: The PyThread_acquire_lock_timed() function now clamps the timeout if it is too large, rather than aborting the process. Patch by Victor Stinner.
bpo-44687:
BufferedReader.peek()
no longer raisesValueError
when the entire file has already been buffered.bpo-45116: Add the
Py_ALWAYS_INLINE
macro to ask the compiler to always inline a static inline function. The compiler can ignore it and decides to not inline the function. Patch by Victor Stinner.bpo-45094: Add the
Py_NO_INLINE
macro to disable inlining on a function. Patch by Victor Stinner.bpo-45061: Add a deallocator to the
bool
type to detect refcount bugs in C extensions which callPy_DECREF(Py_True);
orPy_DECREF(Py_False);
by mistake. Patch by Victor Stinner.bpo-42035: Add a new
PyType_GetQualName()
function to get type’s qualified name.bpo-41103: Reverts removal of the old buffer protocol because they are part of stable ABI.
bpo-44751: Remove
crypt.h
include from the publicPython.h
header.bpo-42747: The
Py_TPFLAGS_HAVE_VERSION_TAG
type flag now does nothing. ThePy_TPFLAGS_HAVE_AM_SEND
flag (which was added in 3.10) is removed. Both were unnecessary because it is not possible to have type objects with the relevant fields missing.bpo-44530: Added the
co_qualname
to thePyCodeObject
structure to propagate the qualified name from the compiler to code objects.Patch by Gabriele N. Tornetta
bpo-44441:
Py_RunMain()
now resetsPyImport_Inittab
to its initial value at exit. It must be possible to callPyImport_AppendInittab()
orPyImport_ExtendInittab()
at each Python initialization. Patch by Victor Stinner.bpo-39947: Remove 4 private trashcan C API functions which were only kept for the backward compatibility of the stable ABI with Python 3.8 and older, since the trashcan API was not usable with the limited C API on Python 3.8 and older. The trashcan API was excluded from the limited C API in Python 3.9.
Removed functions:
_PyTrash_deposit_object()
_PyTrash_destroy_chain()
_PyTrash_thread_deposit_object()
_PyTrash_thread_destroy_chain()
The trashcan C API was never usable with the limited C API, since old trashcan macros accessed directly
PyThreadState
members like_tstate->trash_delete_nesting
, whereas thePyThreadState
structure is opaque in the limited C API.Exclude also the
PyTrash_UNWIND_LEVEL
constant from the C API.Patch by Victor Stinner.
bpo-40939: Removed documentation for the removed
PyParser_*
C API.bpo-43795: The list in Contents of Limited API now shows the public name
PyFrameObject
rather than_frame
. The non-existing entry_node
no longer appears in the list.bpo-44378:
Py_IS_TYPE()
no longer usesPy_TYPE()
to avoid a compiler warning: no longer castconst PyObject*
toPyObject*
. Patch by Victor Stinner.bpo-39573: Convert the
Py_TYPE()
andPy_SIZE()
macros to static inline functions. ThePy_SET_TYPE()
andPy_SET_SIZE()
functions must now be used to set an object type and size. Patch by Victor Stinner.bpo-44263: The
PyType_Ready()
function now raises an error if a type is defined with thePy_TPFLAGS_HAVE_GC
flag set but has no traverse function (PyTypeObject.tp_traverse
). Patch by Victor Stinner.bpo-43795: The undocumented function
Py_FrozenMain()
is removed from the Limited API.bpo-44113: Deprecate the following functions to configure the Python initialization:
PySys_HasWarnOptions()
_Py_SetProgramFullPath()
Use the new
PyConfig
API of the Python Initialization Configuration instead (PEP 587).bpo-44094: Remove
PyErr_SetFromErrnoWithUnicodeFilename()
,PyErr_SetFromWindowsErrWithUnicodeFilename()
, andPyErr_SetExcFromWindowsErrWithUnicodeFilename()
. They are not documented and have been deprecated since Python 3.3.bpo-43795:
PyCodec_Unregister()
is now properly exported as a function in the Windows Stable ABI DLL.bpo-44029: Remove deprecated
Py_UNICODE
APIs:PyUnicode_Encode
,PyUnicode_EncodeUTF7
,PyUnicode_EncodeUTF8
,PyUnicode_EncodeUTF16
,PyUnicode_EncodeUTF32
,PyUnicode_EncodeLatin1
,PyUnicode_EncodeMBCS
,PyUnicode_EncodeDecimal
,PyUnicode_EncodeRawUnicodeEscape
,PyUnicode_EncodeCharmap
,PyUnicode_EncodeUnicodeEscape
,PyUnicode_TransformDecimalToASCII
,PyUnicode_TranslateCharmap
,PyUnicodeEncodeError_Create
,PyUnicodeTranslateError_Create
. See PEP 393 and PEP 624 for reference.bpo-42035: Add a new
PyType_GetName()
function to get type’s short name.
Python 3.10.0 beta 1¶
Release date: 2021-05-03
Security¶
bpo-43434: Creating
sqlite3.Connection
objects now also producessqlite3.connect
andsqlite3.connect/handle
auditing events. Previously these events were only produced bysqlite3.connect()
calls. Patch by Erlend E. Aasland.bpo-43998: The
ssl
module sets more secure cipher suites defaults. Ciphers without forward secrecy and with SHA-1 MAC are disabled by default. Security level 2 prohibits weak RSA, DH, and ECC keys with less than 112 bits of security.SSLContext
defaults to minimum protocol version TLS 1.2. Settings are based on Hynek Schlawack’s research.bpo-43882: The presence of newline or tab characters in parts of a URL could allow some forms of attacks.
Following the controlling specification for URLs defined by WHATWG
urllib.parse()
now removes ASCII newlines and tabs from URLs, preventing such attacks.bpo-43472: Ensures interpreter-level audit hooks receive the
cpython.PyInterpreterState_New
event when called through the_xxsubinterpreters
module.bpo-43362: Fix invalid free in _sha3 module. The issue was introduced in 3.10.0a1. Python 3.9 and earlier are not affected.
bpo-43762: Add audit events for
sqlite3.connect/handle()
,sqlite3.Connection.enable_load_extension()
, andsqlite3.Connection.load_extension()
. Patch by Erlend E. Aasland.bpo-43756: Add new audit event
glob.glob/2
to incorporate the new root_dir and dir_fd arguments added toglob.glob()
andglob.iglob()
.bpo-36384:
ipaddress
module no longer accepts any leading zeros in IPv4 address strings. Leading zeros are ambiguous and interpreted as octal notation by some libraries. For example the legacy functionsocket.inet_aton()
treats leading zeros as octal notation. glibc implementation of moderninet_pton()
does not accept any leading zeros. For a while theipaddress
module used to accept ambiguous leading zeros.bpo-43075: Fix Regular Expression Denial of Service (ReDoS) vulnerability in
urllib.request.AbstractBasicAuthHandler
. The ReDoS-vulnerable regex has quadratic worst-case complexity and it allows cause a denial of service when identifying crafted invalid RFCs. This ReDoS issue is on the client side and needs remote attackers to control the HTTP server.bpo-42800: Audit hooks are now fired for frame.f_code, traceback.tb_frame, and generator code/frame attribute access.
bpo-37363: Add audit events to the
http.client
module.
Core and Builtins¶
bpo-43977: Prevent classes being both a sequence and a mapping when pattern matching.
bpo-43977: Use
tp_flags
on the class object to determine if the subject is a sequence or mapping when pattern matching. Avoids the need to importcollections.abc
when pattern matching.bpo-43892: Restore proper validation of complex literal value patterns when parsing
match
blocks.bpo-43933: Set frame.f_lineno to the line number of the ‘with’ kweyword when executing the call to
__exit__
.bpo-43933: If the current position in a frame has no line number then set the f_lineno attribute to None, instead of -1, to conform to PEP 626. This should not normally be possible, but might occur in some unusual circumstances.
bpo-43963: Importing the
_signal
module in a subinterpreter has no longer side effects.bpo-42739: The internal representation of line number tables is changed to not use sentinels, and an explicit length parameter is added to the out of process API function
PyLineTable_InitAddressRange
. This makes the handling of line number tables more robust in some circumstances.bpo-43908: Make
re
types immutable. Patch by Erlend E. Aasland.bpo-43908: Make the
array.array
type immutable. Patch by Erlend E. Aasland.bpo-43901: Change class and module objects to lazy-create empty annotations dicts on demand. The annotations dicts are stored in the object’s __dict__ for backwards compatibility.
bpo-43892: Match patterns now use new dedicated AST nodes (
MatchValue
,MatchSingleton
,MatchSequence
,MatchStar
,MatchMapping
,MatchClass
) rather than reusing expression AST nodes.MatchAs
andMatchOr
are now defined as pattern nodes rather than as expression nodes. Patch by Nick Coghlan.bpo-42725: Usage of
await
/yield
/yield from
and named expressions within an annotation is now forbidden when PEP 563 is activated.bpo-43754: When performing structural pattern matching (PEP 634), captured names are now left unbound until the entire pattern has matched successfully.
bpo-42737: Annotations for complex targets (everything beside simple names) no longer cause any runtime effects with
from __future__ import annotations
.bpo-43914:
SyntaxError
exceptions raised by the interpreter will highlight the full error range of the expression that consistutes the syntax error itself, instead of just where the problem is detected. Patch by Pablo Galindo.bpo-38605: Revert making
from __future__ import annotations
the default. This follows the Steering Council decision to postpone PEP 563 changes to at least Python 3.11. See the original email for more information regarding the decision: https://mail.python.org/archives/list/python-dev@python.org/thread/CLVXXPQ2T2LQ5MP2Y53VVQFCXYWQJHKZ/. Patch by Pablo Galindo.bpo-43475: Hashes of NaN values now depend on object identity. Formerly, they always hashed to 0 even though NaN values are not equal to one another. Having the same hash for unequal values caused pile-ups in hash tables.
bpo-43859: Improve the error message for
IndentationError
exceptions. Patch by Pablo Galindobpo-41323: Constant tuple folding in bytecode optimizer now reuses tuple in constant table.
bpo-43846: Data stack usage is much reduced for large literal and call expressions.
bpo-38530: When printing
NameError
raised by the interpreter,PyErr_Display()
will offer suggestions of similar variable names in the function that the exception was raised from. Patch by Pablo Galindobpo-43823: Improve syntax errors for invalid dictionary literals. Patch by Pablo Galindo.
bpo-43822: Improve syntax errors in the parser for missing commas between expressions. Patch by Pablo Galindo.
bpo-43798:
ast.alias
nodes now include source location metadata attributes e.g. lineno, col_offset.bpo-43797: Improve
SyntaxError
error messages for invalid comparisons. Patch by Pablo Galindo.bpo-43760: Move the flag for checking whether tracing is enabled to the C stack, from the heap. Should speed up dispatch in the interpreter.
bpo-43682: Static methods (
@staticmethod
) and class methods (@classmethod
) now inherit the method attributes (__module__
,__name__
,__qualname__
,__doc__
,__annotations__
) and have a new__wrapped__
attribute. Patch by Victor Stinner.bpo-43751: Fixed a bug where
anext(ait, default)
would erroneously return None.bpo-42128:
__match_args__
is no longer allowed to be a list.bpo-43683: Add GEN_START opcode. Marks start of generator, including async, or coroutine and handles sending values to a newly created generator or coroutine.
bpo-43105: Importlib now resolves relative paths when creating module spec objects from file locations.
bpo-43682: Static methods (
@staticmethod
) are now callable as regular functions. Patch by Victor Stinner.bpo-42609: Prevented crashes in the AST validator and optimizer when compiling some absurdly long expressions like
"+0"*1000000
.RecursionError
is now raised instead.bpo-38530: When printing
AttributeError
,PyErr_Display()
will offer suggestions of similar attribute names in the object that the exception was raised from. Patch by Pablo Galindo
Library¶
bpo-44015: In @dataclass(), raise a TypeError if KW_ONLY is specified more than once.
bpo-25478: Added a total() method to collections.Counter() to compute the sum of the counts.
bpo-43733: Change
netrc.netrc
to use UTF-8 encoding before using locale encoding.bpo-43979: Removed an unnecessary list comprehension before looping from
urllib.parse.parse_qsl()
. Patch by Christoph Zwerschke and Dong-hee Na.bpo-43993: Update bundled pip to 21.1.1.
bpo-43957: [Enum] Deprecate
TypeError
when non-member is used in a containment check; In 3.12True
orFalse
will be returned instead, and containment will returnTrue
if the value is either a member of that enum or one of its members’ value.bpo-42904: For backwards compatibility with previous minor versions of Python, if
typing.get_type_hints()
receives no namespace dictionary arguments,typing.get_type_hints()
will search through the global then local namespaces during evaluation of stringized type annotations (string forward references) inside a class.bpo-43945: [Enum] Deprecate non-standard mixin format() behavior: in 3.12 the enum member, not the member’s value, will be used for format() calls.
bpo-41139: Deprecate undocumented
cgi.log()
API.bpo-43937: Fixed the
turtle
module working with non-default root window.bpo-43930: Update bundled pip to 21.1 and setuptools to 56.0.0
bpo-43907: Fix a bug in the pure-Python pickle implementation when using protocol 5, where bytearray instances that occur several time in the pickled object graph would incorrectly unpickle into repeated copies of the bytearray object.
bpo-43926: In
importlib.metadata
, provide a uniform interface toDescription
, allow for any field to be encoded with multiline values, remove continuation lines from multiline values, and add a.json
property for easy access to the PEP 566 JSON-compatible form. Sync withimportlib_metadata 4.0
.bpo-43920: OpenSSL 3.0.0:
load_verify_locations()
now returns a consistent error message when cadata contains no valid certificate.bpo-43607:
urllib
can now convert Windows paths with\\?\
prefixes into URL paths.bpo-43817: Add
inspect.get_annotations()
, which safely computes the annotations defined on an object. It works around the quirks of accessing the annotations from various types of objects, and makes very few assumptions about the object passed in.inspect.get_annotations()
can also correctly un-stringize stringized annotations.inspect.signature()
,inspect.from_callable()
, andinspect.from_function()
now callinspect.get_annotations()
to retrieve annotations. This meansinspect.signature()
andinspect.from_callable()
can now un-stringize stringized annotations, too.bpo-43284: platform.win32_ver derives the windows version from sys.getwindowsversion().platform_version which in turn derives the version from kernel32.dll (which can be of a different version than Windows itself). Therefore change the platform.win32_ver to determine the version using the platform module’s _syscmd_ver private function to return an accurate version.
bpo-42854: The
ssl
module now usesSSL_read_ex
andSSL_write_ex
internally. The functions support reading and writing of data larger than 2 GB. Writing zero-length data no longer fails with a protocol violation error.bpo-42333: Port
_ssl
extension module to multiphase initialization.bpo-43880:
ssl
now raises DeprecationWarning for OP_NO_SSL/TLS* options, old TLS versions, old protocols, and other features that have been deprecated since Python 3.6, 3.7, or OpenSSL 1.1.0.bpo-41559: PEP 612 is now implemented purely in Python; builtin
types.GenericAlias
objects no longer includetyping.ParamSpec
in__parameters__
(with the exception ofcollections.abc.Callable
‘sGenericAlias
). This means previously invalid uses ofParamSpec
(such aslist[P]
) which worked in earlier versions of Python 3.10 alpha, will now raiseTypeError
during substitution.bpo-43867: The
multiprocessing
Server
class now explicitly catchesSystemExit
and closes the client connection in this case. It happens when theServer.serve_client()
method reaches the end of file (EOF).bpo-40443: Remove unused imports: pyclbr no longer uses copy, and typing no longer uses ast. Patch by Victor Stinner.
bpo-43820: Remove an unneeded copy of the namespace passed to dataclasses.make_dataclass().
bpo-43787: Add
__iter__()
method tobz2.BZ2File
,gzip.GzipFile
, andlzma.LZMAFile
. It makes iterating them about 2x faster. Patch by Inada Naoki.bpo-43680: Deprecate io.OpenWrapper and _pyio.OpenWrapper: use io.open and _pyio.open instead. Until Python 3.9, _pyio.open was not a static method and builtins.open was set to OpenWrapper to not become a bound method when set to a class variable. _io.open is a built-in function whereas _pyio.open is a Python function. In Python 3.10, _pyio.open() is now a static method, and builtins.open() is now io.open().
bpo-43680: The Python
_pyio.open()
function becomes a static method to behave asio.open()
built-in function: don’t become a bound method when stored as a class variable. It becomes possible since static methods are now callable in Python 3.10. Moreover,_pyio.OpenWrapper()
becomes a simple alias to_pyio.open()
. Patch by Victor Stinner.bpo-41515: Fix
KeyError
raised intyping.get_type_hints()
due to synthetic modules that don’t appear insys.modules
.bpo-43776: When
subprocess.Popen
args are provided as a string or aspathlib.Path
, the Popen instance repr now shows the right thing.bpo-42248: [Enum] ensure exceptions raised in
_missing__
are releasedbpo-43744: fix issue with enum member name matching the start of a private variable name
bpo-43772: Fixed the return value of
TypeVar.__ror__
. Patch by Jelle Zijlstra.bpo-43764: Add match_args parameter to @dataclass decorator to allow suppression of __match_args__ generation.
bpo-43799: OpenSSL 3.0.0: define
OPENSSL_API_COMPAT
1.1.1 to suppress deprecation warnings. Python requires OpenSSL 1.1.1 APIs.bpo-43478: Mocks can no longer be used as the specs for other Mocks. As a result, an already-mocked object cannot have an attribute mocked using
autospec=True
or be the subject of acreate_autospec(...)
call. This can uncover bugs in tests since these Mock-derived Mocks will always pass certain tests (e.g.isinstance()
) and builtin assert functions (e.g. assert_called_once_with) will unconditionally pass.bpo-43794: Add
ssl.OP_IGNORE_UNEXPECTED_EOF
constants (OpenSSL 3.0.0)bpo-43785: Improve
bz2.BZ2File
performance by removing the RLock from BZ2File. This makes BZ2File thread unsafe in the face of multiple simultaneous readers or writers, just like its equivalent classes ingzip
andlzma
have always been. Patch by Inada Naoki.bpo-43789: OpenSSL 3.0.0: Don’t call the password callback function a second time when first call has signaled an error condition.
bpo-43788: The header files for
ssl
error codes are now OpenSSL version-specific. Exceptions will now show correct reason and library codes. Themake_ssl_data.py
script has been rewritten to use OpenSSL’s text file with error codes.bpo-43766: Implement PEP 647 in the
typing
module by addingTypeGuard
.bpo-25264:
os.path.realpath()
now accepts a strict keyword-only argument. When set toTrue
,OSError
is raised if a path doesn’t exist or a symlink loop is encountered.bpo-43780: In
importlib.metadata
, incorporate changes from importlib_metadata 3.10: Add mtime-based caching during distribution discovery. Flagged use of dict result fromentry_points()
as deprecated.The
P.args
andP.kwargs
attributes oftyping.ParamSpec
are now instances of the new classestyping.ParamSpecArgs
andtyping.ParamSpecKwargs
, which enables a more usefulrepr()
. Patch by Jelle Zijlstra.bpo-43731: Add an
encoding
parameterlogging.fileConfig()
.bpo-43712: Add
encoding
anderrors
parameters tofileinput.input()
andfileinput.FileInput
.bpo-38659: A
simple_enum
decorator is added to theenum
module to convert a normal class into an Enum.test_simple_enum
added to test simple enums against a corresponding normal Enum. Standard library modules updated to usesimple_enum
.bpo-43764: Fix an issue where
__match_args__
generation could fail for somedataclasses
.bpo-43752: Fix
sqlite3
regression for zero-sized blobs with converters, whereb""
was returned instead ofNone
. The regression was introduced by PR 24723. Patch by Erlend E. Aasland.bpo-43655:
tkinter
dialog windows are now recognized as dialogs by window managers on macOS and X Window.bpo-43723: The following
threading
methods are now deprecated and should be replaced:currentThread
=>threading.current_thread()
activeCount
=>threading.active_count()
Condition.notifyAll
=>threading.Condition.notify_all()
Event.isSet
=>threading.Event.is_set()
Thread.setName
=>threading.Thread.name
thread.getName
=>threading.Thread.name
Thread.isDaemon
=>threading.Thread.daemon
Thread.setDaemon
=>threading.Thread.daemon
Patch by Jelle Zijlstra.
bpo-2135: Deprecate find_module() and find_loader() implementations in importlib and zipimport.
bpo-43534:
turtle.textinput()
andturtle.numinput()
create now a transient window working on behalf of the canvas window.bpo-43532: Add the ability to specify keyword-only fields to dataclasses. These fields will become keyword-only arguments to the generated __init__.
bpo-43522: Fix problem with
hostname_checks_common_name
. OpenSSL does not copy hostflags from struct SSL_CTX to struct SSL.bpo-8978: Improve error message for
tarfile.open()
whenlzma
/bz2
are unavailable. Patch by Anthony Sottile.bpo-42967: Allow
bytes
separator
argument inurllib.parse.parse_qs
andurllib.parse.parse_qsl
when parsingstr
query strings. Previously, this raised aTypeError
.bpo-43296: Improve
sqlite3
error handling:sqlite3_value_blob()
errors that setSQLITE_NOMEM
now raiseMemoryError
. Patch by Erlend E. Aasland.bpo-43312: New functions
sysconfig.get_preferred_scheme()
andsysconfig.get_default_scheme()
are added to query a platform for its preferred “user”, “home”, and “prefix” (default) scheme names.bpo-43265: Improve
sqlite3.Connection.backup()
error handling. The error message for non-existent target database names is nowunknown database <database name>
instead ofSQL logic error
. Patch by Erlend E. Aasland.bpo-41282: Install schemes in
distutils.command.install
are now loaded fromsysconfig
.bpo-41282:
distutils.sysconfig
has been merged tosysconfig
.bpo-43176: Fixed processing of a dataclass that inherits from a frozen dataclass with no fields. It is now correctly detected as an error.
bpo-43080:
pprint
now has support fordataclasses.dataclass
. Patch by Lewis Gaul.bpo-39950: Add
pathlib.Path.hardlink_to()
method that supersedeslink_to()
. The new method has the same argument order assymlink_to()
.bpo-42904:
typing.get_type_hints()
now checks the local namespace of a class when evaluating PEP 563 annotations inside said class.bpo-42269: Add
slots
parameter todataclasses.dataclass
decorator to automatically generate__slots__
for class. Patch provided by Yurii Karabas.bpo-39529: Deprecated use of
asyncio.get_event_loop()
without running event loop. Emit deprecation warning forasyncio
functions which implicitly create aFuture
orTask
objects if there is no running event loop and no explicit loop argument is passed:ensure_future()
,wrap_future()
,gather()
,shield()
,as_completed()
and constructors ofFuture
,Task
,StreamReader
,StreamReaderProtocol
.bpo-18369: Certificate and PrivateKey classes were added to the ssl module. Certificates and keys can now be loaded from memory buffer, too.
bpo-41486: Use a new output buffer management code for
bz2
/lzma
/zlib
modules, and add.readall()
function to_compression.DecompressReader
class. These bring some performance improvements. Patch by Ma Lin.bpo-31870: The
ssl.get_server_certificate()
function now has a timeout parameter.bpo-41735: Fix thread locks in zlib module may go wrong in rare case. Patch by Ma Lin.
bpo-36470: Fix dataclasses with
InitVar
s andreplace()
. Patch by Claudiu Popa.bpo-40849: Expose X509_V_FLAG_PARTIAL_CHAIN ssl flag
bpo-35114:
ssl.RAND_status()
now returns a boolean value (as documented) instead of1
or0
.bpo-39906:
pathlib.Path.stat()
andchmod()
now accept a follow_symlinks keyword-only argument for consistency with corresponding functions in theos
module.bpo-39899:
os.path.expanduser()
now refuses to guess Windows home directories if the basename of current user’s home directory does not match their username.pathlib.Path.expanduser()
andhome()
now consistently raiseRuntimeError
exception when a home directory cannot be resolved. Previously aKeyError
exception could be raised on Windows when the"USERNAME"
environment variable was unset.bpo-36076: Added SNI support to
ssl.get_server_certificate()
.bpo-38490: Covariance, Pearson’s correlation, and simple linear regression functionality was added to statistics module. Patch by Tymoteusz Wołodźko.
bpo-33731: Provide a locale.localize() function, which converts a normalized number string into a locale format.
bpo-32745: Fix a regression in the handling of ctypes’
ctypes.c_wchar_p
type: embedded null characters would cause aValueError
to be raised. Patch by Zackery Spytz.
Documentation¶
bpo-43987: Add “Annotations Best Practices” document as a new HOWTO.
bpo-43977: Document the new
Py_TPFLAGS_MAPPING
andPy_TPFLAGS_SEQUENCE
type flags.bpo-43959: The documentation on the PyContextVar C-API was clarified.
bpo-43938: Update dataclasses documentation to express that FrozenInstanceError is derived from AttributeError.
bpo-43778: Fix the Sphinx glossary_search extension: create the _static/ sub-directory if it doesn’t exist.
bpo-43755: Update documentation to reflect that unparenthesized lambda expressions can no longer be the expression part in an
if
clause in comprehensions and generator expressions since Python 3.9.bpo-43739: Fixing the example code in Doc/extending/extending.rst to declare and initialize the pmodule variable to be of the right type.
Tests¶
bpo-43961: Fix test_logging.test_namer_rotator_inheritance() on Windows: use
os.replace()
rather thanos.rename()
. Patch by Victor Stinner.bpo-43842: Fix a race condition in the SMTP test of test_logging. Don’t close a file descriptor (socket) from a different thread while asyncore.loop() is polling the file descriptor. Patch by Victor Stinner.
bpo-43843:
test.libregrtest
now marks a test as ENV_CHANGED (altered the execution environment) if a thread raises an exception but does not catch it. It sets a hook onthreading.excepthook()
. Use--fail-env-changed
option to mark the test as failed. Patch by Victor Stinner.bpo-43811: Tests multiple OpenSSL versions on GitHub Actions. Use ccache to speed up testing.
bpo-43791: OpenSSL 3.0.0: Disable testing of legacy protocols TLS 1.0 and 1.1. Tests are failing with TLSV1_ALERT_INTERNAL_ERROR.
Build¶
Windows¶
bpo-35306: Adds additional arguments to
os.startfile()
function.bpo-43538: Avoid raising errors from
pathlib.Path.exists()
when passed an invalid filename.bpo-38822: Fixed
os.stat()
failing on inaccessible directories with a trailing slash, rather than falling back to the parent directory’s metadata. This implicitly affectedos.path.exists()
andos.path.isdir()
.bpo-26227: Fixed decoding of host names in
socket.gethostbyaddr()
andsocket.gethostbyname_ex()
.bpo-40432: Updated pegen regeneration script on Windows to find and use Python 3.8 or higher. Prior to this, pegen regeneration already required 3.8 or higher, but the script may have used lower versions of Python.
bpo-43745: Actually updates Windows release to OpenSSL 1.1.1k. Earlier releases were mislabelled and actually included 1.1.1i again.
bpo-43652: Update Tcl and Tk to 8.6.11 in Windows installer.
bpo-43492: Upgrade Windows installer to use SQLite 3.35.5.
bpo-30555: Fix
WindowsConsoleIO
errors in the presence of fd redirection. Patch by Segev Finer.
macOS¶
bpo-42119: Fix check for macOS SDK paths when building Python. Narrow search to match contents of SDKs, namely only files in
/System/Library
,/System/IOSSupport
, and/usr
other than/usr/local
. Previously, anything under/System
was assumed to be in an SDK which causes problems with the new file system layout in 10.15+ where user file systems may appear to be mounted under/System
. Paths in/Library
were also incorrectly treated as SDK locations.bpo-43568: Drop support for MACOSX_DEPLOYMENT_TARGET < 10.3
bpo-44009: Provide “python3.x-intel64” executable to allow reliably forcing macOS universal2 framework builds to run under Rosetta 2 Intel-64 emulation on Apple Silicon Macs. This can be useful for testing or when universal2 wheels are not yet available.
bpo-43851: Build SQLite with
SQLITE_OMIT_AUTOINIT
on macOS. Patch by Erlend E. Aasland.bpo-43492: Update macOS installer to use SQLite 3.35.4.
bpo-42235:
Mac/BuildScript/build-installer.py
will now use “–enable-optimizations” and--with-lto
when building on macOS 10.15 or later.
IDLE¶
bpo-37903: Add mouse actions to the shell sidebar. Left click and optional drag selects one or more lines, as with the editor line number sidebar. Right click after selecting raises a context menu with ‘copy with prompts’. This zips together prompts from the sidebar with lines from the selected text.
bpo-43981: Fix reference leak in test_sidebar and test_squeezer. Patches by Terry Jan Reedy and Pablo Galindo
bpo-37892: Indent IDLE Shell input with spaces instead of tabs
bpo-43655: IDLE dialog windows are now recognized as dialogs by window managers on macOS and X Window.
bpo-37903: IDLE’s shell now shows prompts in a separate side-bar.
C API¶
bpo-43916: Add a new
Py_TPFLAGS_DISALLOW_INSTANTIATION
type flag to disallow creating type instances. Patch by Victor Stinner.bpo-43774: Remove the now unused
PYMALLOC_DEBUG
macro. Debug hooks on memory allocators are now installed by default if Python is built in debug mode (ifPy_DEBUG
macro is defined). Moreover, they can now be used on Python build in release mode (ex: usingPYTHONMALLOC=debug
environment variable).bpo-43962: _PyInterpreterState_IDIncref() now calls _PyInterpreterState_IDInitref() and always increments id_refcount. Previously, calling _xxsubinterpreters.get_current() could create an id_refcount inconsistency when a _xxsubinterpreters.InterpreterID object was deallocated. Patch by Victor Stinner.
bpo-28254: Add new C-API functions to control the state of the garbage collector:
PyGC_Enable()
,PyGC_Disable()
,PyGC_IsEnabled()
, corresponding to the functions in thegc
module.bpo-43908: Introduce
Py_TPFLAGS_IMMUTABLETYPE
flag for immutable type objects, and modifyPyType_Ready()
to set it for static types. Patch by Erlend E. Aasland.bpo-43795:
PyMem_Calloc()
is now available in the limited C API (Py_LIMITED_API
).bpo-43868:
PyOS_ReadlineFunctionPointer()
is no longer exported by limited C API headers and bypython3.dll
on Windows. Like any function that takesFILE*
, it is not part of the stable ABI.bpo-43795: Stable ABI and limited API definitions are generated from a central manifest (PEP 652).
bpo-43753: Add the
Py_Is(x, y)
function to test if the x object is the y object, the same asx is y
in Python. Add also thePy_IsNone()
,Py_IsTrue()
,Py_IsFalse()
functions to test if an object is, respectively, theNone
singleton, theTrue
singleton or theFalse
singleton. Patch by Victor Stinner.
Python 3.10.0 alpha 7¶
Release date: 2021-04-05
Security¶
bpo-42988: CVE-2021-3426: Remove the
getfile
feature of thepydoc
module which could be abused to read arbitrary files on the disk (directory traversal vulnerability). Moreover, even source code of Python modules can contain sensitive data like passwords. Vulnerability reported by David Schwörer.bpo-43285:
ftplib
no longer trusts the IP address value returned from the server in response to the PASV command by default. This prevents a malicious FTP server from using the response to probe IPv4 address and port combinations on the client network.Code that requires the former vulnerable behavior may set a
trust_server_pasv_ipv4_address
attribute on theirftplib.FTP
instances toTrue
to re-enable it.bpo-43439: Add audit hooks for
gc.get_objects()
,gc.get_referrers()
andgc.get_referents()
. Patch by Pablo Galindo.
Core and Builtins¶
bpo-27129: Update CPython bytecode magic number.
bpo-43672: Raise ImportWarning when calling find_loader().
bpo-43660: Fix crash that happens when replacing
sys.stderr
with a callable that can remove the object while an exception is being printed. Patch by Pablo Galindo.bpo-27129: The bytecode interpreter uses instruction, rather byte, offsets internally. This reduces the number of EXTENDED_ARG instructions needed and streamlines instruction dispatch a bit.
bpo-40645: Fix reference leak in the
_hashopenssl
extension. Patch by Pablo Galindo.bpo-42134: Calls to find_module() by the import system now raise ImportWarning.
bpo-41064: Improve the syntax error for invalid usage of double starred elements (‘**’) in f-strings. Patch by Pablo Galindo.
bpo-43575: Speed up calls to
map()
by using the PEP 590vectorcall
calling convention. Patch by Dong-hee Na.bpo-42137: The import system now prefers using
__spec__
forModuleType.__repr__
overmodule_repr()
.bpo-43452: Added micro-optimizations to
_PyType_Lookup()
to improve cache lookup performance in the common case of cache hits.bpo-43555: Report the column offset for
SyntaxError
for invalid line continuation characters. Patch by Pablo Galindo.bpo-43517: Fix misdetection of circular imports when using
from pkg.mod import attr
, which caused false positives in non-trivial multi-threaded code.bpo-43497: Emit SyntaxWarnings for assertions with tuple constants, this is a regression introduced in python3.7
bpo-39316: Tracing now has correct line numbers for attribute accesses when the attribute is on a different line from the object. Improves debugging and profiling for multi-line method chains.
bpo-35883: Python no longer fails at startup with a fatal error if a command line argument contains an invalid Unicode character. The
Py_DecodeLocale()
function now escapes byte sequences which would be decoded as Unicode characters outside the [U+0000; U+10ffff] range.bpo-43410: Fix a bug that was causing the parser to crash when emitting syntax errors when reading input from stdin. Patch by Pablo Galindo
bpo-43406: Fix a possible race condition where
PyErr_CheckSignals
tries to execute a non-Python signal handler.bpo-42128: Add
__match_args__
tostructsequence
based classes. Patch by Pablo Galindo.bpo-43390: CPython now sets the
SA_ONSTACK
flag inPyOS_setsig
for the VM’s default signal handlers. This is friendlier to other in-process code that an extension module or embedding use could pull in (such as Golang’s cgo) where tiny thread stacks are the norm andsigaltstack()
has been used to provide for signal handlers. This is a no-op change for the vast majority of processes that don’t use sigaltstack.bpo-43287: Speed up calls to
filter()
by using the PEP 590vectorcall
calling convention. Patch by Dong-hee Na.bpo-37448: Add a radix tree based memory map to track in-use obmalloc arenas. Use to replace the old implementation of address_in_range(). The radix tree approach makes it easy to increase pool sizes beyond the OS page size. Boosting the pool and arena size allows obmalloc to handle a significantly higher percentage of requests from its ultra-fast paths.
It also has the advantage of eliminating the memory unsanitary behavior of the previous address_in_range(). The old address_in_range() was marked with the annotations _Py_NO_SANITIZE_ADDRESS, _Py_NO_SANITIZE_THREAD, and _Py_NO_SANITIZE_MEMORY. Those annotations are no longer needed.
To disable the radix tree map, set a preprocessor flag as follows:
-DWITH_PYMALLOC_RADIX_TREE=0
.Co-authored-by: Tim Peters <tim.peters@gmail.com>
bpo-29988: Only handle asynchronous exceptions and requests to drop the GIL when returning from a call or on the back edges of loops. Makes sure that
__exit__()
is always called in with statements, even for interrupts.
Library¶
bpo-43720: Document various stdlib deprecations in imp, pkgutil, and importlib.util for removal in Python 3.12.
bpo-43433:
xmlrpc.client.ServerProxy
no longer ignores query and fragment in the URL of the server.bpo-31956: The
index()
method ofarray.array
now has optional start and stop parameters.bpo-40066: Enum: adjust
repr()
to show only enum and member name (not value, nor angle brackets) andstr()
to show only member name. Update and improve documentation to match.bpo-42136: Deprecate all module_repr() methods found in importlib as their use is being phased out by Python 3.12.
bpo-35930: Raising an exception raised in a “future” instance will create reference cycles.
bpo-41369: Finish updating the vendored libmpdec to version 2.5.1. Patch by Stefan Krah.
bpo-43422: Revert the _decimal C API which was added in bpo-41324.
bpo-43577: Fix deadlock when using
ssl.SSLContext
debug callback withssl.SSLContext.sni_callback()
.bpo-43571: It’s now possible to create MPTCP sockets with IPPROTO_MPTCP
bpo-43542:
image/heic
andimage/heif
were added tomimetypes
.bpo-40645: The
hmac
module now uses OpenSSL’s HMAC implementation when digestmod argument is a hash name or builtin hash function.bpo-43510: Implement PEP 597: Add
EncodingWarning
warning,-X warn_default_encoding
option,PYTHONWARNDEFAULTENCODING
environment variable andencoding="locale"
argument value.bpo-43521:
ast.unparse
can now render NaNs and empty sets.bpo-42914:
pprint.pprint()
gains a new booleanunderscore_numbers
optional argument to emit integers with thousands separated by an underscore character for improved readability (for example1_000_000
instead of1000000
).bpo-41361:
rotate()
calls are now slightly faster due to faster argument parsing.bpo-43423:
subprocess.communicate()
no longer raises an IndexError when there is an empty stdout or stderr IO buffer during a timeout on Windows.bpo-27820: Fixed long-standing bug of smtplib.SMTP where doing AUTH LOGIN with initial_response_ok=False will fail.
The cause is that SMTP.auth_login _always_ returns a password if provided with a challenge string, thus non-compliant with the standard for AUTH LOGIN.
Also fixes bug with the test for smtpd.
bpo-43445: Add frozen modules to
sys.stdlib_module_names
. For example, add"_frozen_importlib"
and"_frozen_importlib_external"
names.bpo-43245: Add keyword arguments support to
ChainMap.new_child()
.bpo-29982: Add optional parameter ignore_cleanup_errors to
tempfile.TemporaryDirectory()
and allow multiplecleanup()
attempts. Contributed by C.A.M. Gerlach.bpo-43428: Include changes from importlib_metadata 3.7:
Performance enhancements to distribution discovery.
entry_points
only returns unique distributions.Introduces new
EntryPoints
object for containing a set of entry points with convenience methods for selecting entry points by group or name.entry_points
now returns this object if selection parameters are supplied but continues to return a dict object for compatibility. Users are encouraged to rely on the selection interface. The dict object result is likely to be deprecated in the future.Added packages_distributions function to return a mapping of packages to the distributions that provide them.
bpo-43332: Improves the networking efficiency of
http.client
when using a proxy viaset_tunnel()
. Fewer small send calls are made during connection setup.bpo-43420: Improve performance of
fractions.Fraction
arithmetics for large components. Contributed by Sergey B. Kirpichev.bpo-43356: Allow passing a signal number to
_thread.interrupt_main()
.bpo-43399: Fix
ElementTree.extend
not working on iterators when using the Python implementationbpo-43369: Improve
sqlite3
error handling: Ifsqlite3_column_text()
andsqlite3_column_blob()
setSQLITE_NOMEM
,MemoryError
is now raised. Patch by Erlend E. Aasland.bpo-43368: Fix a regression introduced in PR 24562, where an empty bytestring was fetched as
None
instead ofb''
insqlite3
. Patch by Mariusz Felisiak.bpo-41282: Fixed stacklevel of
DeprecationWarning
emitted fromimport distutils
.bpo-42129:
importlib.resources
now honors namespace packages, merging resources from each location in the namespace as introduced inimportlib_resources
3.2 and including incidental changes through 5.0.3.bpo-43295:
datetime.datetime.strptime()
now raisesValueError
instead ofIndexError
when matching'z'
with the%z
format specifier.bpo-43125: Return empty string if base64mime.body_encode receive empty bytes
bpo-43084:
curses.window.enclose()
returns nowTrue
orFalse
(as was documented) instead of1
or0
.bpo-42994: Add MIME types for opus, AAC, 3gpp and 3gpp2
bpo-14678: Add an invalidate_caches() method to the zipimport.zipimporter class to support importlib.invalidate_caches(). Patch by Desmond Cheong.
bpo-42782: Fail fast in
shutil.move()
to avoid creating destination directories on failure.bpo-40066: Enum’s
repr()
andstr()
have changed:repr()
is now EnumClass.MemberName andstr()
is MemberName. Additionally, stdlib Enum’s whose contents are available as module attributes, such asRegexFlag.IGNORECASE
, have theirrepr()
as module.name, e.g.re.IGNORECASE
.bpo-26053: Fixed bug where the
pdb
interactive run command echoed the args from the shell command line, even if those have been overridden at the pdb prompt.bpo-24160: Fixed bug where breakpoints did not persist across multiple debugger sessions in
pdb
’s interactive mode.bpo-40701: When the
tempfile.tempdir
global variable is set to a value of type bytes, it is now handled consistently. Previously exceptions could be raised from some tempfile APIs when the directory did not already exist in this situation. Also ensures that thetempfile.gettempdir()
andtempfile.gettempdirb()
functions always returnstr
andbytes
respectively.bpo-39342: Expose
X509_V_FLAG_ALLOW_PROXY_CERTS
asVERIFY_ALLOW_PROXY_CERTS
to allow proxy certificate validation as explained in https://www.openssl.org/docs/man1.1.1/man7/proxy-certificates.html.bpo-31861: Add builtins.aiter and builtins.anext. Patch by Joshua Bronson (@jab), Daniel Pope (@lordmauve), and Justin Wang (@justin39).
Documentation¶
bpo-43199: Answer “Why is there no goto?” in the Design and History FAQ.
bpo-43407: Clarified that a result from
time.monotonic()
,time.perf_counter()
,time.process_time()
, ortime.thread_time()
can be compared with the result from any following call to the same function - not just the next immediate call.bpo-43354: Fix type documentation for
Fault.faultCode
; the type has to beint
instead ofstr
.bpo-41933: Clarified wording of s * n in the Common Sequence Operations
Tests¶
Build¶
bpo-43179: Introduce and correctly use ALIGNOF_X in place of SIZEOF_X for alignment-related code in optimized string routines. Patch by Jessica Clarke.
bpo-43631: Update macOS, Windows, and CI to OpenSSL 1.1.1k.
bpo-43617: Improve configure.ac: Check for presence of autoconf-archive package and remove our copies of M4 macros.
bpo-43466: The
configure
script now supports--with-openssl-rpath
option.bpo-43372: Use
_freeze_importlib
to generate code for the__hello__
module. This approach ensures the code matches the interpreter version. Previously, PYTHON_FOR_REGEN was used to generate the code, which might be wrong. The marshal format for code objects has changed with bpo-42246, commit 877df851. Update the code and the expected code sizes in ctypes test_frozentable.
Windows¶
IDLE¶
bpo-42225: Document that IDLE can fail on Unix either from misconfigured IP masquerade rules or failure displaying complex colored (non-ascii) characters.
C API¶
bpo-43688: The limited C API is now supported if Python is built in debug mode (if the
Py_DEBUG
macro is defined). In the limited C API, thePy_INCREF()
andPy_DECREF()
functions are now implemented as opaque function calls, rather than accessing directly thePyObject.ob_refcnt
member, if Python is built in debug mode and thePy_LIMITED_API
macro targets Python 3.10 or newer. It became possible to support the limited C API in debug mode because thePyObject
structure is the same in release and debug mode since Python 3.8 (see bpo-36465).The limited C API is still not supported in the
--with-trace-refs
special build (Py_TRACE_REFS
macro).Patch by Victor Stinner.
bpo-43244: Remove the
pyarena.h
header file with functions:PyArena_New()
PyArena_Free()
PyArena_Malloc()
PyArena_AddPyObject()
These functions were undocumented, excluded from the limited C API, and were only used internally by the compiler. Patch by Victor Stinner.
bpo-43244: Remove the compiler and parser functions using
struct _mod
type, because the public AST C API was removed:PyAST_Compile()
PyAST_CompileEx()
PyAST_CompileObject()
PyFuture_FromAST()
PyFuture_FromASTObject()
PyParser_ASTFromFile()
PyParser_ASTFromFileObject()
PyParser_ASTFromFilename()
PyParser_ASTFromString()
PyParser_ASTFromStringObject()
These functions were undocumented and excluded from the limited C API. Patch by Victor Stinner.
bpo-43244: Remove
ast.h
,asdl.h
, andPython-ast.h
header files. These functions were undocumented and excluded from the limited C API. Most names defined by these header files were not prefixed byPy
and so could create names conflicts. For example,Python-ast.h
defined aYield
macro which was conflict with theYield
name used by the Windows<winbase.h>
header. Use the Pythonast
module instead. Patch by Victor Stinner.bpo-43541: Fix a
PyEval_EvalCodeEx()
regression: fix reference counting on builtins. Patch by Victor Stinner.bpo-43244: Remove the
symtable.h
header file and the undocumented functions:PyST_GetScope()
PySymtable_Build()
PySymtable_BuildObject()
PySymtable_Free()
Py_SymtableString()
Py_SymtableStringObject()
The
Py_SymtableString()
function was part the stable ABI by mistake but it could not be used, because thesymtable.h
header file was excluded from the limited C API.The Python
symtable
module remains available and is unchanged.Patch by Victor Stinner.
bpo-43244: Remove the
PyAST_Validate()
function. It is no longer possible to build a AST object (mod_ty
type) with the public C API. The function was already excluded from the limited C API (PEP 384). Patch by Victor Stinner.
Python 3.10.0 alpha 6¶
Release date: 2021-03-01
Security¶
bpo-42967: Fix web cache poisoning vulnerability by defaulting the query args separator to
&
, and allowing the user to choose a custom separator.
Core and Builtins¶
bpo-43321: Fix
SystemError
raised whenPyArg_Parse*()
is used with#
but withoutPY_SSIZE_T_CLEAN
defined.bpo-36346:
PyArg_Parse*()
functions now emitsDeprecationWarning
whenu
orZ
format is used. See PEP 623 for detail.bpo-43277: Add a new
PySet_CheckExact()
function to the C-API to check if an object is an instance ofset
but not an instance of a subtype. Patch by Pablo Galindo.bpo-42990: The
types.FunctionType
constructor now inherits the current builtins if the globals dictionary has no"__builtins__"
key, rather than using{"None": None}
as builtins: same behavior aseval()
andexec()
functions. Defining a function withdef function(...): ...
in Python is not affected, globals cannot be overridden with this syntax: it also inherits the current builtins. Patch by Victor Stinner.bpo-42990: Functions have a new
__builtins__
attribute which is used to look for builtin symbols when a function is executed, instead of looking into__globals__['__builtins__']
. Patch by Mark Shannon and Victor Stinner.bpo-43149: Improve the error message in the parser for exception groups without parentheses. Patch by Pablo Galindo.
bpo-43121: Fixed an incorrect
SyntaxError
message for missing comma in literals. Patch by Pablo Galindo.bpo-42819:
readline
: Explicitly disable bracketed paste in the interactive interpreter, even if it’s set in the inputrc, is enabled by default (eg GNU Readline 8.1), or a user callsreadline.read_init_file()
. The Python REPL has not implemented bracketed paste support. Also, bracketed mode writes the"\x1b[?2004h"
escape sequence into stdout which causes test failures in applications that don’t support it. It can still be explicitly enabled by callingreadline.parse_and_bind("set enable-bracketed-paste on")
. Patch by Dustin Rodrigues.bpo-42808: Simple calls to
type(object)
are now faster due to thevectorcall
calling convention. Patch by Dennis Sweeney.bpo-42217: Make the compiler merges same co_code and co_linetable objects in a module like already did for co_consts.
bpo-41972: Substring search functions such as
str1 in str2
andstr2.find(str1)
now sometimes use the “Two-Way” string comparison algorithm to avoid quadratic behavior on long strings.bpo-42128: Implement PEP 634 (structural pattern matching). Patch by Brandt Bucher.
bpo-40692: In the
concurrent.futures.ProcessPoolExecutor
, validate thatmultiprocess.synchronize()
is available on a given platform and rely on that check in theconcurrent.futures
test suite so we can run tests that are unrelated toProcessPoolExecutor
on those platforms.bpo-38302: If
object.__ipow__()
returnsNotImplemented
, the operator will correctly fall back toobject.__pow__()
andobject.__rpow__()
as expected.
Library¶
bpo-43316: The
python -m gzip
command line application now properly fails when detecting an unsupported extension. It exits with a non-zero exit code and prints an error message to stderr.bpo-43317: Set the chunk size for the
gzip
module main function to io.DEFAULT_BUFFER_SIZE. This is slightly faster than the 1024 bytes constant that was used previously.bpo-43146: Handle None in single-arg versions of
print_exception()
andformat_exception()
.bpo-43260: Fix TextIOWrapper can not flush internal buffer forever after very large text is written.
bpo-43258: Prevent needless allocation of
sqlite3
aggregate function context when no rows match an aggregate query. Patch by Erlend E. Aasland.bpo-43251: Improve
sqlite3
error handling:sqlite3_column_name()
failures now result inMemoryError
. Patch by Erlend E. Aasland.bpo-40956: Fix segfault in
sqlite3.Connection.backup()
if no argument was provided. The regression was introduced by PR 23838. Patch by Erlend E. Aasland.bpo-43172: The readline module now passes its tests when built directly against libedit. Existing irreconcilable API differences remain in
readline.get_begidx()
andreadline.get_endidx()
behavior based on libreadline vs libedit use.bpo-43163: Fix a bug in
codeop
that was causing it to not ask for more input when multi-line snippets have unclosed parentheses. Patch by Pablo Galindobpo-43162: deprecate unsupported ability to access enum members as attributes of other enum members
bpo-43146: Fix recent regression in None argument handling in
traceback
module functions.bpo-43102: The namedtuple __new__ method had its __builtins__ set to None instead of an actual dictionary. This created problems for introspection tools.
bpo-43106: Added
O_EVTONLY
,O_FSYNC
,O_SYMLINK
andO_NOFOLLOW_ANY
for macOS. Patch by Dong-hee Na.bpo-42960: Adds
resource.RLIMIT_KQUEUES
constant from FreeBSD to theresource
module.bpo-42151: Make the pure Python implementation of
xml.etree.ElementTree
behave the same as the C implementation (_elementree
) regarding default attribute values (by not settingspecified_attributes=1
).bpo-29753: In ctypes, now packed bitfields are calculated properly and the first item of packed bitfields is now shrank correctly.
Documentation¶
Tests¶
bpo-43288: Fix test_importlib to correctly skip Unicode file tests if the filesystem does not support them.
Build¶
bpo-43174: Windows build now uses
/utf-8
compiler option.bpo-43103: Add a new configure
--without-static-libpython
option to not build thelibpythonMAJOR.MINOR.a
static library and not install thepython.o
object file.bpo-13501: The configure script can now use libedit instead of readline with the command line option
--with-readline=editline
.bpo-42603: Make configure script use pkg-config to detect the location of Tcl/Tk headers and libraries, used to build tkinter.
On macOS, a Tcl/Tk configuration provided by pkg-config will be preferred over Tcl/Tk frameworks installed in
/{System/,}Library/Frameworks
. If both exist and the latter is preferred, the appropriate--with-tcltk-*
configuration options need to be explicitly set.bpo-39448: Add the “regen-frozen” makefile target that regenerates the code for the frozen
__hello__
module.
Windows¶
bpo-43155:
PyCMethod_New()
is now present inpython3.lib
.
macOS¶
bpo-41837: Update macOS installer build to use OpenSSL 1.1.1j.
IDLE¶
bpo-43283: Document why printing to IDLE’s Shell is often slower than printing to a system terminal and that it can be made faster by pre-formatting a single string before printing.
C API¶
bpo-43278: Always put compiler and system information on the first line of the REPL welcome message.
bpo-43270: Remove the private
_PyErr_OCCURRED()
macro: use the publicPyErr_Occurred()
function instead.bpo-35134: Move odictobject.h, parser_interface.h, picklebufobject.h, pydebug.h, and pyfpe.h into the cpython/ directory. They must not be included directly, as they are already included by Python.h: Include Files.
bpo-35134: Move pyarena.h, pyctype.h, and pytime.h into the cpython/ directory. They must not be included directly, as they are already included by Python.h: Include Files.
bpo-40170:
PyExceptionClass_Name()
is now always declared as a function, in order to hide implementation details. The macro accessedPyTypeObject.tp_name
directly. Patch by Erlend E. Aasland.bpo-43239: The
PyCFunction_New()
function is now exported in the ABI when compiled with-fvisibility=hidden
.bpo-40170:
PyIter_Check()
is now always declared as a function, in order to hide implementation details. The macro accessedPyTypeObject.tp_iternext
directly. Patch by Erlend E. Aasland.bpo-40170: Convert
PyDescr_IsData()
macro to a function to hide implementation details: The macro accessedPyTypeObject.tp_descr_set
directly. Patch by Erlend E. Aasland.bpo-43181: Convert
PyObject_TypeCheck()
macro to a static inline function. Patch by Erlend E. Aasland.
Python 3.10.0 alpha 5¶
Release date: 2021-02-02
Security¶
bpo-42938: Avoid static buffers when computing the repr of
ctypes.c_double
andctypes.c_longdouble
values.
Core and Builtins¶
bpo-42990: Refactor the
PyEval_
family of functions.An new function
_PyEval_Vector
is added to simplify calls to Python from C._PyEval_EvalCodeWithName
is removedPyEval_EvalCodeEx
is retained as part of the API, but is not used internally
bpo-38631: Replace
Py_FatalError()
calls in the compiler with regularSystemError
exceptions. Patch by Victor Stinner.bpo-42997: Improve error message for missing “:” before blocks. Patch by Pablo Galindo.
bpo-43017: Improve error message in the parser when using un-parenthesised tuples in comprehensions. Patch by Pablo Galindo.
bpo-42986: Fix parser crash when reporting syntax errors in f-string with newlines. Patch by Pablo Galindo.
bpo-40176: Syntax errors for unterminated string literals now point to the start of the string instead of reporting EOF/EOL.
bpo-42927: The inline cache for
LOAD_ATTR
now also optimizes access to attributes defined by__slots__
. This makes reading such attribute up to 30% faster.bpo-42864: Improve error messages in the parser when parentheses are not closed. Patch by Pablo Galindo.
bpo-42924: Fix
bytearray
repetition incorrectly copying data from the start of the buffer, even if the data is offset within the buffer (e.g. after reassigning a slice at the start of thebytearray
to a shorter byte string).bpo-42882: Fix the
_PyUnicode_FromId()
function (_Py_IDENTIFIER(var) API) whenPy_Initialize()
/Py_Finalize()
is called multiple times: preserve_PyRuntime.unicode_ids.next_index
value.bpo-42827: Fix a crash when working out the error line of a
SyntaxError
in some multi-line expressions.bpo-42823: frame.f_lineno is correct even if frame.f_trace is set to True
bpo-37324: Remove deprecated aliases to Collections Abstract Base Classes from the
collections
module.bpo-41994: Fixed possible leak in
import
whensys.modules
is not adict
.bpo-27772: In string formatting, preceding the width field by
'0'
no longer affects the default alignment for strings.
Library¶
bpo-43108: Fixed a reference leak in the
curses
module. Patch by Pablo Galindobpo-43077: Update the bundled pip to 21.0.1 and setuptools to 52.0.0.
bpo-41282: Deprecate
distutils
in documentation and add warning on import.bpo-43014: Improve performance of
tokenize
by 20-30%. Patch by Anthony Sottile.bpo-42323: Fix
math.nextafter()
for NaN on AIX.bpo-42955: Add
sys.stdlib_module_names
, containing the list of the standard library module names. Patch by Victor Stinner.bpo-42944: Fix
random.Random.sample
whencounts
argument is notNone
.bpo-42934: Use
TracebackException
’s newcompact
param inTestResult
to reduce time and memory consumed by traceback formatting.bpo-42931: Add
randbytes()
torandom.__all__
.bpo-38250: [Enum] Flags consisting of a single bit are now considered canonical, and will be the only flags returned from listing and iterating over a Flag class or a Flag member. Multi-bit flags are considered aliases; they will be returned from lookups and operations that result in their value. Iteration for both Flag and Flag members is in definition order.
bpo-42877: Added the
compact
parameter to the constructor oftraceback.TracebackException
to reduce time and memory for use cases that only need to callTracebackException.format()
andTracebackException.format_exception_only()
.bpo-42923: The
Py_FatalError()
function and thefaulthandler
module now dump the list of extension modules on a fatal error.bpo-42848: Removed recursion from
TracebackException
to allow it to handle long exception chains.bpo-42901: [Enum] move member creation from
EnumMeta.__new__
to_proto_member.__set_name__
, allowing members to be created and visible in__init_subclass__
.bpo-42780: Fix os.set_inheritable() for O_PATH file descriptors on Linux.
bpo-42866: Fix a reference leak in the
getcodec()
function of CJK codecs. Patch by Victor Stinner.bpo-42846: Convert the 6 CJK codec extension modules (_codecs_cn, _codecs_hk, _codecs_iso2022, _codecs_jp, _codecs_kr and _codecs_tw) to the multiphase initialization API (PEP 489). Patch by Victor Stinner.
bpo-42851: remove __init_subclass__ support for Enum members
bpo-42834: Make internal caches of the
_json
module compatible with subinterpreters.bpo-41748: Fix HTMLParser parsing rules for element attributes containing commas with spaces. Patch by Karl Dubost.
bpo-40810: Require SQLite 3.7.15 or newer. Patch by Erlend E. Aasland.
bpo-1635741: Convert the _multibytecodec extension module (CJK codecs) to multi-phase initialization (PEP 489). Patch by Erlend E. Aasland.
bpo-42802: The distutils
bdist_wininst
command deprecated in Python 3.8 has been removed. The distutilsbdist_wheel
command is now recommended to distribute binary packages on Windows.bpo-24464: The undocumented built-in function
sqlite3.enable_shared_cache
is now deprecated, scheduled for removal in Python 3.12. Its use is strongly discouraged by the SQLite3 documentation. Patch by Erlend E. Aasland.bpo-42384: Make pdb populate sys.path[0] exactly the same as regular python execution.
bpo-42383: Fix pdb: previously pdb would fail to restart the debugging target if it was specified using a relative path and the current directory changed.
bpo-42005: Fix CLI of
cProfile
andprofile
to catchBrokenPipeError
.bpo-41604: Don’t decrement the reference count of the previous user_ptr when set_panel_userptr fails.
bpo-41149: Allow executing callables that have a boolean value of
False
when passed toThreading.thread
as the target. Patch contributed by Barney Stratford.bpo-38307: Add an ‘end_lineno’ attribute to the Class and Function objects that appear in the tree returned by pyclbr functions. This and the existing ‘lineno’ attribute define the extent of class and def statements. Patch by Aviral Srivastava.
bpo-39273: The
BUTTON5_*
constants are now exposed in thecurses
module if available.bpo-33289: Correct call to
tkinter.colorchooser
to return RGB triplet of ints instead of floats. Patch by Cheryl Sabella.
Documentation¶
Tests¶
Build¶
bpo-43031: Pass
--timeout=$(TESTTIMEOUT)
option to the default profile task./python -m test --pgo
command.bpo-36143:
make regen-all
now also runsregen-keyword
. Patch by Victor Stinner.bpo-42874: Removed the grep -q and -E flags in the tzpath validation section of the configure script to better accommodate users of some platforms (specifically Solaris 10).
bpo-31904: Add library search path by wr-cc in add_cross_compiling_paths() for VxWorks.
bpo-42856: Add
--with-wheel-pkg-dir=PATH
option to the./configure
script. If specified, theensurepip
module looks forsetuptools
andpip
wheel packages in this directory: if both are present, these wheel packages are used instead of ensurepip bundled wheel packages.Some Linux distribution packaging policies recommend against bundling dependencies. For example, Fedora installs wheel packages in the
/usr/share/python-wheels/
directory and don’t install theensurepip._bundled
package.
Windows¶
macOS¶
bpo-42504: Ensure that the value of sysconfig.get_config_var(‘MACOSX_DEPLOYMENT_TARGET’) is always a string, even in when the value is parsable as an integer.
IDLE¶
bpo-43008: Make IDLE invoke
sys.excepthook()
in normal, 2-process mode. Patch by Ken Hilton.bpo-33065: Fix problem debugging user classes with __repr__ method.
bpo-23544: Disable Debug=>Stack Viewer when user code is running or Debugger is active, to prevent hang or crash. Patch by Zackery Spytz.
bpo-32631: Finish zzdummy example extension module: make menu entries work; add docstrings and tests with 100% coverage.
C API¶
bpo-42979: When Python is built in debug mode (with C assertions), calling a type slot like
sq_length
(__len__()
in Python) now fails with a fatal error if the slot succeeded with an exception set, or failed with no exception set. The error message contains the slot, the type name, and the current exception (if an exception is set). Patch by Victor Stinner.bpo-43030: Fixed a compiler warning in
Py_UNICODE_ISSPACE()
on platforms with signedwchar_t
.
Python 3.10.0 alpha 4¶
Release date: 2021-01-04
Core and Builtins¶
bpo-42814: Fix undefined behavior in
Objects/genericaliasobject.c
.bpo-42806: Fix the column offsets for f-strings
ast
nodes surrounded by parentheses and for nodes that spawn multiple lines. Patch by Pablo Galindo.bpo-40631: Fix regression where a single parenthesized starred expression was a valid assignment target.
bpo-27794: Improve the error message for failed writes/deletes to property objects. When possible, the attribute name is now shown. Patch provided by Yurii Karabas.
bpo-42745: Make the type attribute lookup cache per-interpreter. Patch by Victor Stinner.
bpo-42246: Jumps to jumps are not eliminated when it would break PEP 626.
bpo-42246: Make sure that the
f_lasti
andf_lineno
attributes of a frame are set correctly when an exception is raised or re-raised. Required for PEP 626.bpo-32381: The coding cookie (ex:
# coding: latin1
) is now ignored in the command passed to the-c
command line option. Patch by Victor Stinner.bpo-30858: Improve error location in expressions that contain assignments. Patch by Pablo Galindo and Lysandros Nikolaou.
bpo-42615: Remove jump commands made redundant by the deletion of unreachable bytecode blocks
bpo-42639: Make the
atexit
module state per-interpreter. It is now safe have more than oneatexit
module instance. Patch by Dong-hee Na and Victor Stinner.bpo-32381: Fix encoding name when running a
.pyc
file on Windows:PyRun_SimpleFileExFlags()
now uses the correct encoding to decode the filename.bpo-42195: The
__args__
of the parameterized generics fortyping.Callable
andcollections.abc.Callable
are now consistent. The__args__
forcollections.abc.Callable
are now flattened whiletyping.Callable
’s have not changed. To allow this change,types.GenericAlias
can now be subclassed andcollections.abc.Callable
’s__class_getitem__
will now return a subclass oftypes.GenericAlias
. Tests for typing were also updated to not subclass things likeCallable[..., T]
as that is not a valid base class. Finally, bothCallable
s no longer validate theirargtypes
, inCallable[[argtypes], resulttype]
to prepare for PEP 612. Patch by Ken Jin.bpo-40137: Convert functools module to use
PyType_FromModuleAndSpec()
.bpo-40077: Convert
array
to use heap types, and establish module state for these.bpo-42008: Fix _random.Random() seeding.
bpo-1635741: Port the
pyexpat
extension module to multi-phase initialization (PEP 489).bpo-40521: Make the Unicode dictionary of interned strings compatible with subinterpreters. Patch by Victor Stinner.
bpo-39465: Make
_PyUnicode_FromId()
function compatible with subinterpreters. Each interpreter now has an array of identifier objects (interned strings decoded from UTF-8). Patch by Victor Stinner.
Library¶
bpo-42257: Handle empty string in variable executable in platform.libc_ver()
bpo-42772: randrange() now raises a TypeError when step is specified without a stop argument. Formerly, it silently ignored the step argument.
bpo-42759: Fixed equality comparison of
tkinter.Variable
andtkinter.font.Font
. Objects which belong to different Tcl interpreters are now always different, even if they have the same name.bpo-42756: Configure LMTP Unix-domain socket to use socket global default timeout when a timeout is not explicitly provided.
bpo-23328: Allow / character in username, password fields on _PROXY envars.
bpo-42740:
typing.get_args()
andtyping.get_origin()
now support PEP 604 union types and PEP 612 additions toCallable
.bpo-42655:
subprocess
extra_groups is now correctly passed into setgroups() system call.bpo-42727:
EnumMeta.__prepare__
now accepts**kwds
to properly support__init_subclass__
bpo-38308: Add optional weights to statistics.harmonic_mean().
bpo-42721: When simple query dialogs (
tkinter.simpledialog
), message boxes (tkinter.messagebox
) or color choose dialog (tkinter.colorchooser
) are created without arguments master and parent, and the default root window is not yet created, andNoDefaultRoot()
was not called, a new temporal hidden root window will be created automatically. It will not be set as the default root window and will be destroyed right after closing the dialog window. It will help to use these simple dialog windows in programs which do not need other GUI.bpo-25246: Optimized
collections.deque.remove()
.bpo-35728: Added a root parameter to
tkinter.font.nametofont()
.bpo-15303:
tkinter
supports now widgets with boolean value False.bpo-42681: Fixed range checks for color and pair numbers in
curses
.bpo-42685: Improved placing of simple query windows in Tkinter (such as
tkinter.simpledialog.askinteger()
). They are now centered at the center of the parent window if it is specified and shown, otherwise at the center of the screen.bpo-9694: Argparse help no longer uses the confusing phrase, “optional arguments”. It uses “options” instead.
bpo-1635741: Port the
_thread
extension module to the multiphase initialization API (PEP 489) and convert its static types to heap types.bpo-37961: Fix crash in
tracemalloc.Traceback.__repr__()
(regressed in Python 3.9).bpo-42630:
tkinter
functions and constructors which need a default root window raise nowRuntimeError
with descriptive message instead of obscureAttributeError
orNameError
if it is not created yet or cannot be created automatically.bpo-42639:
atexit._run_exitfuncs()
now logs callback exceptions usingsys.unraisablehook
, rather than logging them directly intosys.stderr
and raise the last exception.bpo-42644:
logging.disable
will now validate the types and value of its parameter. It also now accepts strings representing the levels (as doesloging.setLevel
) instead of only the numerical values.bpo-42639: At Python exit, if a callback registered with
atexit.register()
fails, its exception is now logged. Previously, only some exceptions were logged, and the last exception was always silently ignored.bpo-36541: Fixed lib2to3.pgen2 to be able to parse PEP-570 positional only argument syntax.
bpo-42382: In
importlib.metadata
: -EntryPoint
objects now expose a.dist
object referencing theDistribution
when constructed from aDistribution
. - Add support for package discovery under package normalization rules. - The object returned bymetadata()
now has a formally-defined protocol calledPackageMetadata
with declared support for the.get_all()
method. - Synced with importlib_metadata 3.3.bpo-41877: A check is added against misspellings of autospect, auto_spec and set_spec being passed as arguments to patch, patch.object and create_autospec.
bpo-39717: [tarfile] update nested exception raising to use
from None
orfrom e
bpo-41877: AttributeError for suspected misspellings of assertions on mocks are now pointing out that the cause are misspelled assertions and also what to do if the misspelling is actually an intended attribute name. The unittest.mock document is also updated to reflect the current set of recognised misspellings.
bpo-41559: Implemented PEP 612: added
ParamSpec
andConcatenate
totyping
. Patch by Ken Jin.bpo-42385: StrEnum: fix _generate_next_value_ to return a str
bpo-31904: Define THREAD_STACK_SIZE for VxWorks.
bpo-34750: [Enum]
_EnumDict.update()
is now supportedbpo-42517: Enum: private names do not become members / do not generate errors – they remain normal attributes
bpo-42678:
Enum
: call__init_subclass__
after members have been addedbpo-28964:
ast.literal_eval()
adds line number information (if available) in error message for malformed nodes.bpo-42470:
random.sample()
no longer warns on a sequence which is also a set.bpo-31904:
posixpath.expanduser()
returns the input path unchanged if user home directory is None on VxWorks.bpo-42388: Fix subprocess.check_output(…, input=None) behavior when text=True to be consistent with that of the documentation and universal_newlines=True.
bpo-34463: Fixed discrepancy between
traceback
and the interpreter in formatting of SyntaxError with lineno not set (traceback
was changed to match interpreter).bpo-42393: Raise
OverflowError
instead of silent truncation insocket.ntohs()
andsocket.htons()
. Silent truncation was deprecated in Python 3.7. Patch by Erlend E. Aaslandbpo-42222: Harmonized
random.randrange()
argument handling to matchrange()
.The integer test and conversion in
randrange()
now usesoperator.index()
.Non-integer arguments to
randrange()
are deprecated.The
ValueError
is deprecated in favor of aTypeError
.It now runs a little faster than before.
(Contributed by Raymond Hettinger and Serhiy Storchaka.)
bpo-42163: Restore compatibility for
uname_result
around deepcopy and _replace.bpo-42090:
zipfile.Path.joinpath
now accepts arbitrary arguments, same aspathlib.Path.joinpath
.bpo-1635741: Port the _csv module to the multi-phase initialization API (PEP 489).
bpo-42059:
typing.TypedDict
types created using the alternative call-style syntax now correctly respect thetotal
keyword argument when setting their__required_keys__
and__optional_keys__
class attributes.bpo-41960: Add
globalns
andlocalns
parameters to theinspect.signature()
andinspect.Signature.from_callable()
.bpo-41907: fix
format()
behavior forIntFlag
bpo-41891: Ensure asyncio.wait_for waits for task completion
bpo-24792: Fixed bug where
zipimporter
sometimes reports an incorrect cause of import errors.bpo-31904: Fix site and sysconfig modules for VxWorks RTOS which has no home directories.
bpo-41462: Add
os.set_blocking()
support for VxWorks RTOS.bpo-40219: Lowered
tkinter.ttk.LabeledScale
dummy widget to prevent hiding part of the content label.bpo-37193: Fixed memory leak in
socketserver.ThreadingMixIn
introduced in Python 3.7.bpo-39068: Fix initialization race condition in
a85encode()
andb85encode()
inbase64
. Patch by Brandon Stansbury.
Documentation¶
bpo-17140: Add documentation for the
multiprocessing.pool.ThreadPool
class.bpo-34398: Prominently feature listings from the glossary in documentation search results. Patch by Ammar Askar.
Tests¶
bpo-42794: Update test_nntplib to use official group name of news.aioe.org for testing. Patch by Dong-hee Na.
bpo-31904: Skip some asyncio tests on VxWorks.
bpo-42641: Enhance
test_select.test_select()
: it now takes 500 milliseconds rather than 10 seconds. Use Python rather than a shell to make the test more portable.bpo-31904: Skip some tests in _test_all_chown_common() on VxWorks.
bpo-42199: Fix bytecode helper assertNotInBytecode.
bpo-41443: Add more attribute checking in test_posix.py
bpo-31904: Disable os.popen and impacted tests on VxWorks
bpo-41439: Port test_ssl and test_uuid to VxWorks RTOS.
Build¶
bpo-42692: Fix __builtin_available check on older compilers. Patch by Joshua Root.
bpo-27640: Added
--disable-test-modules
option to theconfigure
script: don’t build nor install test modules. Patch by Xavier de Gaye, Thomas Petazzoni and Peixing Xin.bpo-42604: Now all platforms use a value for the “EXT_SUFFIX” build variable derived from SOABI (for instance in freeBSD, “EXT_SUFFIX” is now “.cpython-310d.so” instead of “.so”). Previously only Linux, Mac and VxWorks were using a value for “EXT_SUFFIX” that included “SOABI”.
bpo-42598: Fix implicit function declarations in configure which could have resulted in incorrect configuration checks. Patch contributed by Joshua Root.
bpo-31904: Enable libpython3.so for VxWorks.
bpo-29076: Add fish shell support to macOS installer.
macOS¶
Tools/Demos¶
C API¶
bpo-42591: Export the
Py_FrozenMain()
function: fix a Python 3.9.0 regression. Python 3.9 uses-fvisibility=hidden
and the function was not exported explicitly and so not exported.bpo-32381: Remove the private
_Py_fopen()
function which is no longer needed. Use_Py_wfopen()
or_Py_fopen_obj()
instead. Patch by Victor Stinner.bpo-1635741: Port
resource
extension module to module statebpo-42111: Update the
xxlimited
module to be a better example of how to use the limited C API.bpo-40052: Fix an alignment build warning/error in function
PyVectorcall_Function()
. Patch by Andreas Schneider, Antoine Pitrou and Petr Viktorin.
Python 3.10.0 alpha 3¶
Release date: 2020-12-07
Security¶
bpo-40791: Add
volatile
to the accumulator variable inhmac.compare_digest
, making constant-time-defeating optimizations less likely.
Core and Builtins¶
bpo-42576:
types.GenericAlias
will now raise aTypeError
when attempting to initialize with a keyword argument. Previously, this would cause the interpreter to crash if the interpreter was compiled with debug symbols. This does not affect interpreters compiled for release. Patch by Ken Jin.bpo-42536: Several built-in and standard library types now ensure that their internal result tuples are always tracked by the garbage collector:
Previously, they could have become untracked by a prior garbage collection. Patch by Brandt Bucher.
bpo-42500: Improve handling of exceptions near recursion limit. Converts a number of Fatal Errors in RecursionErrors.
bpo-42246: PEP 626: After a return, the f_lineno attribute of a frame is always the last line executed.
bpo-42435: Speed up comparison of bytes objects with non-bytes objects when option
-b
is specified. Speed up comparison of bytarray objects with non-buffer object.bpo-1635741: Port the
_warnings
extension module to the multi-phase initialization API (PEP 489). Patch by Victor Stinner.bpo-41686: On Windows, the
SIGINT
event,_PyOS_SigintEvent()
, is now created even if Python is configured to not install signal handlers (ifPyConfig.install_signal_handlers
equals to 0, orPy_InitializeEx(0)
).bpo-42381: Allow assignment expressions in set literals and set comprehensions as per PEP 572. Patch by Pablo Galindo.
bpo-42202: Change function parameters annotations internal representation to tuple of strings. Patch provided by Yurii Karabas.
bpo-42374: Fix a regression introduced by the new parser, where an unparenthesized walrus operator was not allowed within generator expressions.
bpo-42316: Allow an unparenthesized walrus in subscript indexes.
bpo-42349: Make sure that the compiler front-end produces a well-formed control flow graph. Be be more aggressive in the compiler back-end, as it is now safe to do so.
bpo-42296: On Windows, fix a regression in signal handling which prevented to interrupt a program using CTRL+C. The signal handler can be run in a thread different than the Python thread, in which case the test deciding if the thread can handle signals is wrong.
bpo-42332:
types.GenericAlias
objects can now be the targets of weakrefs.bpo-42282: Optimise constant subexpressions that appear as part of named expressions (previously the AST optimiser did not descend into named expressions). Patch by Nick Coghlan.
bpo-42266: Fixed a bug with the LOAD_ATTR opcode cache that was not respecting monkey-patching a class-level attribute to make it a descriptor. Patch by Pablo Galindo.
bpo-42246: Improved accuracy of line tracing events and f_lineno attribute of Frame objects. See PEP 626 for details.
bpo-42233: Allow
GenericAlias
objects to use union type expressions. This allows expressions likelist[int] | dict[float, str]
where previously aTypeError
would have been thrown. This also fixes union type expressions not de-duplicatingGenericAlias
objects. (Contributed by Ken Jin in bpo-42233.)bpo-26131: The import system triggers a
ImportWarning
when it falls back to usingload_module()
.
Library¶
bpo-5054: CGIHTTPRequestHandler.run_cgi() HTTP_ACCEPT improperly parsed. Replace the special purpose getallmatchingheaders with generic get_all method and add relevant tests.
Original Patch by Martin Panter. Modified by Senthil Kumaran.
bpo-42562: Fix issue when dis failed to parse function that has no line numbers. Patch provided by Yurii Karabas.
bpo-17735:
inspect.findsource()
now raisesOSError
instead ofIndexError
whenco_lineno
of a code object is greater than the file length. This can happen, for example, when a file is edited after it was imported. PR by Irit Katriel.bpo-42116: Fix handling of trailing comments by
inspect.getsource()
.bpo-42532: Remove unexpected call of
__bool__
when passing aspec_arg
argument to a Mock.bpo-38200: Added itertools.pairwise()
bpo-41818: Fix test_master_read() so that it succeeds on all platforms that either raise OSError or return b”” upon reading from master.
bpo-42487: ChainMap.__iter__ no longer calls __getitem__ on underlying maps
bpo-42482:
TracebackException
no longer holds a reference to the exception’s traceback object. Consequently, instances of TracebackException for equivalent but non-equal exceptions now compare as equal.bpo-41818: Make test_openpty() avoid unexpected success due to number of rows and/or number of columns being == 0.
bpo-42392: Remove loop parameter from
asyncio.subprocess
andasyncio.tasks
functions. Patch provided by Yurii Karabas.bpo-42392: Remove loop parameter from
asyncio.open_connection
andasyncio.start_server
functions. Patch provided by Yurii Karabas.bpo-28468: Add
platform.freedesktop_os_release()
function to parse freedesktop.orgos-release
files.bpo-42299: Removed the
formatter
module, which was deprecated in Python 3.4. It is somewhat obsolete, little used, and not tested. It was originally scheduled to be removed in Python 3.6, but such removals were delayed until after Python 2.7 EOL. Existing users should copy whatever classes they use into their code. Patch by Dong-hee Na and and Terry J. Reedy.bpo-26131: Deprecate zipimport.zipimporter.load_module() in favour of exec_module().
bpo-41818: Updated tests for the pty library. test_basic() has been changed to test_openpty(); this additionally checks if slave termios and slave winsize are being set properly by pty.openpty(). In order to add support for FreeBSD, NetBSD, OpenBSD, and Darwin, this also adds test_master_read(), which demonstrates that pty.spawn() should not depend on an OSError to exit from its copy loop.
bpo-42392: Remove loop parameter from
__init__
in allasyncio.locks
andasyncio.Queue
classes. Patch provided by Yurii Karabas.bpo-15450: Make
filecmp.dircmp
respect subclassing. Now thefilecmp.dircmp.subdirs
behaves as expected when subclassing dircmp.bpo-42413: The exception
socket.timeout
is now an alias ofTimeoutError
.bpo-31904: Support signal module on VxWorks.
bpo-42406: We fixed an issue in
pickle.whichmodule
in which importingmultiprocessing
could change the how pickle identifies which module an object belongs to, potentially breaking the unpickling of those objects.bpo-42403: Simplify the
importlib
external bootstrap code:importlib._bootstrap_external
now uses regular imports to import builtin modules. When it is imported, the builtin__import__()
function is already fully working and so can be used to import builtin modules likesys
. Patch by Victor Stinner.bpo-1635741: Convert _sre module types to heap types (PEP 384). Patch by Erlend E. Aasland.
bpo-42375: subprocess module update for DragonFlyBSD support.
bpo-41713: Port the
_signal
extension module to the multi-phase initialization API (PEP 489). Patch by Victor Stinner and Mohamed Koubaa.bpo-37205:
time.time()
,time.perf_counter()
andtime.monotonic()
functions can no longer fail with a Python fatal error, instead raise a regular Python exception on failure.bpo-42328: Fixed
tkinter.ttk.Style.map()
. The function accepts now the representation of the default state as empty sequence (as returned byStyle.map()
). The structure of the result is now the same on all platform and does not depend on the value ofwantobjects
.bpo-42345: Fix various issues with
typing.Literal
parameter handling (flatten, deduplicate, use type to cache key). Patch provided by Yurii Karabas.bpo-37205:
time.perf_counter()
on Windows andtime.monotonic()
on macOS are now system-wide. Previously, they used an offset computed at startup to reduce the precision loss caused by the float type. Usetime.perf_counter_ns()
andtime.monotonic_ns()
added in Python 3.7 to avoid this precision loss.bpo-42318: Fixed support of non-BMP characters in
tkinter
on macOS.bpo-42350: Fix the
threading.Thread
class at fork: do nothing if the thread is already stopped (ex: fork called at Python exit). Previously, an error was logged in the child process.bpo-42333: Port _ssl extension module to heap types.
bpo-42014: The
onerror
callback fromshutil.rmtree
now receives correct function whenos.open
fails.bpo-42237: Fix
os.sendfile()
on illumos.bpo-42308: Add
threading.__excepthook__
to allow retrieving the original value ofthreading.excepthook()
in case it is set to a broken or a different value. Patch by Mario Corchero.bpo-42131: Implement PEP 451/spec methods on zipimport.zipimporter: find_spec(), create_module(), and exec_module().
This also allows for the documented deprecation of find_loader(), find_module(), and load_module().
bpo-41877: Mock objects which are not unsafe will now raise an AttributeError if an attribute with the prefix asert, aseert, or assrt is accessed, in addition to this already happening for the prefixes assert or assret.
bpo-42264:
sqlite3.OptimizedUnicode
has been undocumented and obsolete since Python 3.3, when it was made an alias tostr
. It is now deprecated, scheduled for removal in Python 3.12.bpo-42251: Added
threading.gettrace()
andthreading.getprofile()
to retrieve the functions set bythreading.settrace()
andthreading.setprofile()
respectively. Patch by Mario Corchero.bpo-42249: Fixed writing binary Plist files larger than 4 GiB.
bpo-42236: On Unix, the
os.device_encoding()
function now returns'UTF-8'
rather than the device encoding if the Python UTF-8 Mode is enabled.bpo-41754: webbrowser: Ignore NotADirectoryError when calling
xdg-settings
.bpo-42183: Fix a stack overflow error for asyncio Task or Future repr().
The overflow occurs under some circumstances when a Task or Future recursively returns itself.
bpo-42140: Improve asyncio.wait function to create the futures set just one time.
bpo-42133: Update various modules in the stdlib to fall back on
__spec__.loader
when__loader__
isn’t defined on a module.bpo-26131: The
load_module()
methods found in importlib now trigger a DeprecationWarning.bpo-39825: Windows: Change
sysconfig.get_config_var('EXT_SUFFIX')
to the expected fullplatform_tag.extension
format. Previously it was hard-coded to.pyd
, now it is compatible withdistutils.sysconfig
and will result in something like.cp38-win_amd64.pyd
. This brings windows into conformance with the other platforms.bpo-26389: The
traceback.format_exception()
,traceback.format_exception_only()
, andtraceback.print_exception()
functions can now take an exception object as a positional-only argument.bpo-41889: Enum: fix regression involving inheriting a multiply-inherited enum
bpo-41861: Convert
sqlite3
to use heap types (PEP 384). Patch by Erlend E. Aasland.bpo-40624: Added support for the XPath
!=
operator in xml.etreebpo-28850: Fix
pprint.PrettyPrinter.format()
overrides being ignored for contents of small containers. Thepprint._safe_repr()
function was removed.bpo-41625: Expose the
splice()
asos.splice()
in theos
module. Patch by Pablo Galindobpo-34215: Clarify the error message for
asyncio.IncompleteReadError
whenexpected
isNone
.bpo-41543: Add async context manager support for contextlib.nullcontext.
bpo-21041:
pathlib.PurePath.parents
now supports negative indexing. Patch contributed by Yaroslav Pankovych.bpo-41332: Added missing connect_accepted_socket() method to
asyncio.AbstractEventLoop
.bpo-12800: Extracting a symlink from a tarball should succeed and overwrite the symlink if it already exists. The fix is to remove the existing file or symlink before extraction. Based on patch by Chris AtLee, Jeffrey Kintscher, and Senthil Kumaran.
bpo-40968:
urllib.request
andhttp.client
now sendhttp/1.1
ALPN extension during TLS handshake when no custom context is supplied.bpo-41001: Add func:
os.eventfd
to provide a low level interface for Linux’s event notification file descriptor.bpo-40816: Add AsyncContextDecorator to contextlib to support async context manager as a decorator.
bpo-40550: Fix time-of-check/time-of-action issue in subprocess.Popen.send_signal.
bpo-39411: Add an
is_async
identifier topyclbr
’sFunction
objects. Patch by Batuhan Taskayabpo-35498: Add slice support to
pathlib.PurePath.parents
.
Documentation¶
bpo-42238: Tentative to deprecate
make suspicious
by first removing it from the CI and documentation builds, but keeping it around for manual uses.bpo-42153: Fix the URL for the IMAP protocol documents.
bpo-41028: Language and version switchers, previously maintained in every cpython branches, are now handled by docsbuild-script.
Tests¶
bpo-41473: Re-enable test_gdb on gdb 9.2 and newer: https://bugzilla.redhat.com/show_bug.cgi?id=1866884 bug is fixed in gdb 10.1.
bpo-42553: Fix
test_asyncio.test_call_later()
race condition: don’t measure asyncio performance in thecall_later()
unit test. The test failed randomly on the CI.bpo-31904: Fix test_netrc on VxWorks: create temporary directories using temp_cwd().
bpo-31904: skip test_getaddrinfo_ipv6_scopeid_symbolic and test_getnameinfo_ipv6_scopeid_symbolic on VxWorks
bpo-31904: skip test_test of test_mailcap on VxWorks
bpo-31904: add shell requirement for test_pipes
bpo-31904: skip some tests related to fifo on VxWorks
bpo-31904: Fix test_doctest.py failures for VxWorks.
bpo-40754: Include
_testinternalcapi
module in Windows installer for test suitebpo-41561: test_ssl: skip test_min_max_version_mismatch when TLS 1.0 is not available
bpo-31904: Fix os module failures for VxWorks RTOS.
bpo-31904: Fix fifo test cases for VxWorks RTOS.
Build¶
bpo-31904: remove libnet dependency from detect_socket() for VxWorks
bpo-42398: Fix a race condition in “make regen-all” when make -jN option is used to run jobs in parallel. The clinic.py script now only use atomic write to write files. Moveover, generated files are now left unchanged if the content does not change, to not change the file modification time.
bpo-41617: Fix building
pycore_bitutils.h
internal header on old clang version without__builtin_bswap16()
(ex: Xcode 4.6.3 on Mac OS X 10.7). Patch by Joshua Root and Victor Stinner.bpo-38823: It is no longer possible to build the
_ctypes
extension module withoutwchar_t
type: removeCTYPES_UNICODE
macro. Anyway, thewchar_t
type is required to build Python. Patch by Victor Stinner.bpo-42087: Support was removed for AIX 5.3 and below. See bpo-40680.