| .. date: 2026-03-10-09-46-44 |
| .. gh-issue: 145731 |
| .. nonce: 5uEGgb |
| .. release date: 2026-03-10 |
| .. section: Windows |
| |
| Fix negative timestamp during DST on Windows. Patch by Hugo van Kemenade. |
| |
| .. |
| |
| .. date: 2026-02-27-10-57-20 |
| .. gh-issue: 145307 |
| .. nonce: ueoT7j |
| .. section: Windows |
| |
| Defers loading of the ``psapi.dll`` module until it is used by |
| :func:`ctypes.util.dllist`. |
| |
| .. |
| |
| .. date: 2026-02-13-11-07-51 |
| .. gh-issue: 144551 |
| .. nonce: ENtMYD |
| .. section: Windows |
| |
| Updated bundled version of OpenSSL to 3.5.5. |
| |
| .. |
| |
| .. date: 2026-03-04-17-39-15 |
| .. gh-issue: 144741 |
| .. nonce: 0RHhBF |
| .. section: Tests |
| |
| Fix ``test_frame_pointer_unwind`` when Python is built with |
| :option:`--enable-shared`. Classify also libpython frames as ``"python"``. |
| Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-12-12-12-00 |
| .. gh-issue: 144739 |
| .. nonce: -fx1tN |
| .. section: Tests |
| |
| When Python was compiled with system expat older then 2.7.2 but tests run |
| with newer expat, still skip |
| :class:`!test.test_pyexpat.MemoryProtectionTest`. |
| |
| .. |
| |
| .. date: 2026-03-04-18-59-17 |
| .. gh-issue: 145506 |
| .. nonce: 6hwvEh |
| .. section: Security |
| |
| Fixes :cve:`2026-2297` by ensuring that ``SourcelessFileLoader`` uses |
| :func:`io.open_code` when opening ``.pyc`` files. |
| |
| .. |
| |
| .. date: 2026-01-31-21-56-54 |
| .. gh-issue: 144370 |
| .. nonce: fp9m8t |
| .. section: Security |
| |
| Disallow usage of control characters in status in :mod:`wsgiref.handlers` to |
| prevent HTTP header injections. Patch by Benedikt Johannes. |
| |
| .. |
| |
| .. date: 2026-03-07-15-00-00 |
| .. gh-issue: 145623 |
| .. nonce: 2Y7LzT |
| .. section: Library |
| |
| Fix crash in :mod:`struct` when calling :func:`repr` or ``__sizeof__()`` on |
| an uninitialized :class:`struct.Struct` object created via |
| ``Struct.__new__()`` without calling ``__init__()``. |
| |
| .. |
| |
| .. date: 2026-03-05-19-01-28 |
| .. gh-issue: 145551 |
| .. nonce: gItPRl |
| .. section: Library |
| |
| Fix InvalidStateError when cancelling process created by |
| :func:`asyncio.create_subprocess_exec` or |
| :func:`asyncio.create_subprocess_shell`. Patch by Daan De Meyer. |
| |
| .. |
| |
| .. date: 2026-03-05-16-06-09 |
| .. gh-issue: 141510 |
| .. nonce: dFPAQS |
| .. section: Library |
| |
| :mod:`marshal` now supports :class:`frozendict` objects. The marshal format |
| version was increased to 6. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-03-03-11-49-44 |
| .. gh-issue: 145417 |
| .. nonce: m_HxIL |
| .. section: Library |
| |
| :mod:`venv`: Prevent incorrect preservation of SELinux context when copying |
| the ``Activate.ps1`` script. The script inherited the SELinux security |
| context of the system template directory, rather than the destination |
| project directory. |
| |
| .. |
| |
| .. date: 2026-03-02-20-08-09 |
| .. gh-issue: 145335 |
| .. nonce: lVTBvd |
| .. section: Library |
| |
| ``os.listdir(-1)`` and ``os.scandir(-1)`` now fail with |
| ``OSError(errno.EBADF)`` rather than listing the current directory. |
| ``os.listxattr(-1)`` now fails with ``OSError(errno.EBADF)`` rather than |
| listing extended attributes of the current directory. Patch by Victor |
| Stinner. |
| |
| .. |
| |
| .. date: 2026-03-02-19-41-39 |
| .. gh-issue: 145376 |
| .. nonce: OOzSOh |
| .. section: Library |
| |
| Fix double free and null pointer dereference in unusual error scenarios in |
| :mod:`hashlib` and :mod:`hmac` modules. |
| |
| .. |
| |
| .. date: 2026-02-28-00-55-00 |
| .. gh-issue: 145301 |
| .. nonce: Lk2bRl |
| .. section: Library |
| |
| :mod:`hmac`: fix a crash when the initialization of the underlying C |
| extension module fails. |
| |
| .. |
| |
| .. date: 2026-02-27-19-00-26 |
| .. gh-issue: 145301 |
| .. nonce: 2Wih4b |
| .. section: Library |
| |
| :mod:`hashlib`: fix a crash when the initialization of the underlying C |
| extension module fails. |
| |
| .. |
| |
| .. date: 2026-02-27-18-04-51 |
| .. gh-issue: 76007 |
| .. nonce: 17idfK |
| .. section: Library |
| |
| The ``version`` attribute of the :mod:`tarfile` module is deprecated and |
| slated for removal in Python 3.20. |
| |
| .. |
| |
| .. date: 2026-02-23-20-52-55 |
| .. gh-issue: 145158 |
| .. nonce: vWJtxI |
| .. section: Library |
| |
| Avoid undefined behaviour from signed integer overflow when parsing format |
| strings in the :mod:`struct` module. |
| |
| .. |
| |
| .. date: 2026-02-21-17-34-53 |
| .. gh-issue: 123853 |
| .. nonce: 6RUwWh |
| .. section: Library |
| |
| Removed Windows 95 compatibility for :func:`locale.getdefaultlocale`. |
| |
| .. |
| |
| .. date: 2026-02-20-13-03-10 |
| .. gh-issue: 66802 |
| .. nonce: OYcAi_ |
| .. section: Library |
| |
| Add :func:`unicodedata.block` function to return the `Unicode block |
| <https://www.unicode.org/versions/Unicode17.0.0/core-spec/chapter-3/#G64189>`_ |
| of a character. |
| |
| .. |
| |
| .. date: 2026-02-19-20-54-25 |
| .. gh-issue: 145033 |
| .. nonce: X9EBPQ |
| .. section: Library |
| |
| Add :data:`typing.TypeForm`, implementing :pep:`747`. Patch by Jelle |
| Zijlstra. |
| |
| .. |
| |
| .. date: 2026-02-19-18-02-54 |
| .. gh-issue: 141510 |
| .. nonce: qzvYsO |
| .. section: Library |
| |
| :func:`dataclasses.field`: if *metadata* is ``None``, use an empty |
| :class:`frozendict`, instead of a :func:`~types.MappingProxyType` of an |
| empty :class:`dict`. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-19-17-50-47 |
| .. gh-issue: 145006 |
| .. nonce: 9gqA0Q |
| .. section: Library |
| |
| Add :exc:`ModuleNotFoundError` hints when a module for a different ABI |
| exists. |
| |
| .. |
| |
| .. date: 2026-02-19-16-26-08 |
| .. gh-issue: 141510 |
| .. nonce: 4Qxy8_ |
| .. section: Library |
| |
| ``ParameterizedMIMEHeader.params`` of :mod:`email.headerregistry` is now a |
| :class:`frozendict` instead of a :class:`types.MappingProxyType`. Patch by |
| Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-19-15-42-06 |
| .. gh-issue: 134872 |
| .. nonce: sjYX1- |
| .. section: Library |
| |
| Add valid import name suggestions on :exc:`ModuleNotFoundError`. |
| |
| .. |
| |
| .. date: 2026-02-19-10-57-40 |
| .. gh-issue: 88091 |
| .. nonce: N7qGV- |
| .. section: Library |
| |
| Fix :func:`unicodedata.decomposition` for Hangul characters. |
| |
| .. |
| |
| .. date: 2026-02-19-00-00-00 |
| .. gh-issue: 144986 |
| .. nonce: atexit-leak |
| .. section: Library |
| |
| Fix a memory leak in :func:`atexit.register`. Patch by Shamil Abdulaev. |
| |
| .. |
| |
| .. date: 2026-02-18-13-45-00 |
| .. gh-issue: 144777 |
| .. nonce: R97q0a |
| .. section: Library |
| |
| Fix data races in :class:`io.IncrementalNewlineDecoder` in the |
| :term:`free-threaded build`. |
| |
| .. |
| |
| .. date: 2026-02-18-00-00-00 |
| .. gh-issue: 144809 |
| .. nonce: nYpEUx |
| .. section: Library |
| |
| Make :class:`collections.deque` copy atomic in the :term:`free-threaded |
| build`. |
| |
| .. |
| |
| .. date: 2026-02-17-11-28-37 |
| .. gh-issue: 141510 |
| .. nonce: OpAz0M |
| .. section: Library |
| |
| The :mod:`copy` module now supports the :class:`frozendict` type. Patch by |
| Pieter Eendebak based on work by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-17-11-15-17 |
| .. gh-issue: 141510 |
| .. nonce: ZmqEUb |
| .. section: Library |
| |
| The :mod:`json` module now supports the :class:`frozendict` type. Patch by |
| Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-15-12-02-20 |
| .. gh-issue: 144835 |
| .. nonce: w_oS_J |
| .. section: Library |
| |
| Added missing explanations for some parameters in :func:`glob.glob` and |
| :func:`glob.iglob`. |
| |
| .. |
| |
| .. date: 2026-02-15-00-00-00 |
| .. gh-issue: 144833 |
| .. nonce: TUelo1 |
| .. section: Library |
| |
| Fixed a use-after-free in :mod:`ssl` when ``SSL_new()`` returns NULL in |
| ``newPySSLSocket()``. The error was reported via a dangling pointer after |
| the object had already been freed. |
| |
| .. |
| |
| .. date: 2026-02-14-14-56-44 |
| .. gh-issue: 140715 |
| .. nonce: AbSheM |
| .. section: Library |
| |
| Add ``'%D'`` support to :meth:`~datetime.datetime.strptime`. |
| |
| .. |
| |
| .. date: 2026-02-13-14-20-10 |
| .. gh-issue: 144782 |
| .. nonce: 0Y8TKj |
| .. section: Library |
| |
| Fix :class:`argparse.ArgumentParser` to be :mod:`pickleable <pickle>`. |
| |
| .. |
| |
| .. date: 2026-02-13-11-14-18 |
| .. gh-issue: 144763 |
| .. nonce: cDwnEE |
| .. section: Library |
| |
| Fix a race condition in :mod:`tracemalloc`: it no longer detaches the |
| attached thread state to acquire its internal lock. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-13-00-00-00 |
| .. gh-issue: 142224 |
| .. nonce: BidiMissing |
| .. section: Library |
| |
| :func:`unicodedata.bidirectional` now return the correct default bidi class |
| for unassigned code points. |
| |
| .. |
| |
| .. date: 2026-02-12-17-56-17 |
| .. gh-issue: 117865 |
| .. nonce: jE1ema |
| .. section: Library |
| |
| Reduce the import time of :mod:`inspect` module by ~20%. |
| |
| .. |
| |
| .. date: 2026-02-10-22-05-51 |
| .. gh-issue: 144156 |
| .. nonce: UbrC7F |
| .. section: Library |
| |
| Fix the folding of headers by the :mod:`email` library when :rfc:`2047` |
| encoded words are used. Now whitespace is correctly preserved and also |
| correctly added between adjacent encoded words. The latter property was |
| broken by the fix for gh-92081, which mostly fixed previous failures to |
| preserve whitespace. |
| |
| .. |
| |
| .. date: 2026-02-10-16-56-05 |
| .. gh-issue: 66305 |
| .. nonce: PZ6GN8 |
| .. section: Library |
| |
| Fixed a hang on Windows in the :mod:`tempfile` module when trying to create |
| a temporary file or subdirectory in a non-writable directory. |
| |
| .. |
| |
| .. date: 2026-02-09-02-16-36 |
| .. gh-issue: 144615 |
| .. nonce: s04x4n |
| .. section: Library |
| |
| Methods directly decorated with :deco:`functools.singledispatchmethod` now |
| dispatch on the second argument when called after being accessed as class |
| attributes. Patch by Bartosz Sławecki. |
| |
| .. |
| |
| .. date: 2026-02-08-17-09-10 |
| .. gh-issue: 144321 |
| .. nonce: w58PhQ |
| .. section: Library |
| |
| The functional syntax for creating :class:`typing.NamedTuple` classes now |
| supports passing any :term:`iterable` of fields and types. Previously, only |
| sequences were supported. |
| |
| .. |
| |
| .. date: 2026-02-07-16-37-42 |
| .. gh-issue: 144475 |
| .. nonce: 8tFEXw |
| .. section: Library |
| |
| Calling :func:`repr` on :func:`functools.partial` is now safer when the |
| partial object's internal attributes are replaced while the string |
| representation is being generated. |
| |
| .. |
| |
| .. date: 2026-02-07-16-31-42 |
| .. gh-issue: 144285 |
| .. nonce: iyH9iL |
| .. section: Library |
| |
| Attribute suggestions in :exc:`AttributeError` tracebacks are now formatted |
| differently to make them easier to understand, for example: ``Did you mean |
| '.datetime.now' instead of '.now'``. Contributed by Bartosz Sławecki. |
| |
| .. |
| |
| .. date: 2026-02-03-19-57-41 |
| .. gh-issue: 144316 |
| .. nonce: wop870 |
| .. section: Library |
| |
| Fix crash in ``_remote_debugging`` that caused ``test_external_inspection`` |
| to intermittently fail. Patch by Taegyun Kim. |
| |
| .. |
| |
| .. date: 2026-01-17-08-44-25 |
| .. gh-issue: 143637 |
| .. nonce: qyPqDo |
| .. section: Library |
| |
| Fixed a crash in socket.sendmsg() that could occur if ancillary data is |
| mutated re-entrantly during argument parsing. |
| |
| .. |
| |
| .. date: 2026-01-12-19-39-57 |
| .. gh-issue: 140652 |
| .. nonce: HvM9Bl |
| .. section: Library |
| |
| Fix a crash in :func:`!_interpchannels.list_all` after closing a channel. |
| |
| .. |
| |
| .. date: 2026-01-11-18-35-52 |
| .. gh-issue: 143698 |
| .. nonce: gXDzsJ |
| .. section: Library |
| |
| Allow *scheduler* and *setpgroup* arguments to be explicitly :const:`None` |
| when calling :func:`os.posix_spawn` or :func:`os.posix_spawnp`. Patch by |
| Bénédikt Tran. |
| |
| .. |
| |
| .. date: 2026-01-11-16-59-22 |
| .. gh-issue: 143698 |
| .. nonce: b-Cpeb |
| .. section: Library |
| |
| Raise :exc:`TypeError` instead of :exc:`SystemError` when the *scheduler* in |
| :func:`os.posix_spawn` or :func:`os.posix_spawnp` is not a tuple. Patch by |
| Bénédikt Tran. |
| |
| .. |
| |
| .. date: 2026-01-11-13-03-32 |
| .. gh-issue: 142516 |
| .. nonce: u7An-s |
| .. section: Library |
| |
| :mod:`ssl`: fix reference leaks in :class:`ssl.SSLContext` objects. Patch by |
| Bénédikt Tran. |
| |
| .. |
| |
| .. date: 2026-01-10-22-58-30 |
| .. gh-issue: 85809 |
| .. nonce: 0eW4wt |
| .. section: Library |
| |
| Added :term:`path-like object` support for :func:`shutil.make_archive`. |
| |
| .. |
| |
| .. date: 2026-01-01-05-26-00 |
| .. gh-issue: 143304 |
| .. nonce: Kv7x9Q |
| .. section: Library |
| |
| Fix :class:`ctypes.CDLL` to honor the ``handle`` parameter on POSIX systems. |
| |
| .. |
| |
| .. date: 2025-12-18-00-14-16 |
| .. gh-issue: 142781 |
| .. nonce: gcOeYF |
| .. section: Library |
| |
| :mod:`zoneinfo`: fix a crash when instantiating :class:`~zoneinfo.ZoneInfo` |
| objects for which the internal class-level cache is inconsistent. |
| |
| .. |
| |
| .. date: 2025-12-16-13-34-48 |
| .. gh-issue: 142787 |
| .. nonce: wNitJX |
| .. section: Library |
| |
| Fix assertion failure in :mod:`sqlite3` blob subscript when slicing with |
| indices that result in an empty slice. |
| |
| .. |
| |
| .. date: 2025-12-06-16-14-18 |
| .. gh-issue: 142352 |
| .. nonce: pW5HLX88 |
| .. section: Library |
| |
| Fix :meth:`asyncio.StreamWriter.start_tls` to transfer buffered data from |
| :class:`~asyncio.StreamReader` to the SSL layer, preventing data loss when |
| upgrading a connection to TLS mid-stream (e.g., when implementing PROXY |
| protocol support). |
| |
| .. |
| |
| .. date: 2025-10-10-14-08-58 |
| .. gh-issue: 139899 |
| .. nonce: 09leRY |
| .. section: Library |
| |
| Introduced :meth:`importlib.abc.MetaPathFinder.discover` and |
| :meth:`importlib.abc.PathEntryFinder.discover` to allow module and submodule |
| name discovery without assuming the use of traditional filesystem based |
| imports. |
| |
| .. |
| |
| .. date: 2025-08-04-23-20-43 |
| .. gh-issue: 137335 |
| .. nonce: IIjDJN |
| .. section: Library |
| |
| Get rid of any possibility of a name conflict for named pipes in |
| :mod:`multiprocessing` and :mod:`asyncio` on Windows, no matter how small. |
| |
| .. |
| |
| .. date: 2025-06-24-19-07-18 |
| .. gh-issue: 135883 |
| .. nonce: 38cePA |
| .. section: Library |
| |
| Fix :mod:`sqlite3`'s :ref:`interactive shell <sqlite3-cli>` keeping part of |
| previous commands when scrolling history. |
| |
| .. |
| |
| .. date: 2024-09-30-15-31-59 |
| .. gh-issue: 124748 |
| .. nonce: KYzYFp |
| .. section: Library |
| |
| Improve :exc:`TypeError` error message when |
| :meth:`!weakref.WeakKeyDictionary.update` is used with keyword-only |
| parameters. |
| |
| .. |
| |
| .. date: 2023-02-05-20-02-30 |
| .. gh-issue: 80667 |
| .. nonce: 7LmzeA |
| .. section: Library |
| |
| Add support for Tangut Ideographs names in :mod:`unicodedata`. |
| |
| .. |
| |
| .. bpo: 42353 |
| .. date: 2022-02-05-00-15-03 |
| .. nonce: 0ebVGG |
| .. section: Library |
| |
| The :mod:`re` module gains a new :func:`re.prefixmatch` function as an |
| explicit spelling of what has to date always been known as :func:`re.match`. |
| :class:`re.Pattern` similary gains a :meth:`re.Pattern.prefixmatch` method. |
| |
| Why? Explicit is better than implicit. Other widely used languages all use |
| the term "match" to mean what Python uses the term "search" for. The |
| unadorened "match" name in Python has been a frequent case of confusion and |
| coding bugs due to the inconsistency with the rest if the software industry. |
| |
| We do not plan to deprecate and remove the older ``match`` name. |
| |
| .. |
| |
| .. bpo: 40243 |
| .. date: 2020-04-10-14-29-53 |
| .. nonce: 85HRib |
| .. section: Library |
| |
| Fix :meth:`!unicodedata.ucd_3_2_0.numeric` for non-decimal values. |
| |
| .. |
| |
| .. bpo: 40212 |
| .. date: 2020-04-07-05-09-34 |
| .. nonce: oPYeBs |
| .. section: Library |
| |
| Re-enable :func:`os.posix_fallocate` and :func:`os.posix_fadvise` on AIX. |
| |
| .. |
| |
| .. bpo: 3405 |
| .. date: 2018-05-11-12-26-16 |
| .. nonce: CacMw9 |
| .. section: Library |
| |
| Add support for user data of Tk virtual events and detail for ``Enter``, |
| ``Leave``, ``FocusIn``, ``FocusOut``, and ``ConfigureRequest`` events to |
| :mod:`tkinter`. |
| |
| .. |
| |
| .. bpo: 32234 |
| .. date: 2017-12-15-09-32-57 |
| .. nonce: XaOkhR |
| .. section: Library |
| |
| :class:`mailbox.Mailbox` instances can now be used as a context manager. The |
| Mailbox is locked on context entry and unlocked and closed at context exit. |
| |
| .. |
| |
| .. date: 2026-03-03-08-18-00 |
| .. gh-issue: 145450 |
| .. nonce: VI7GXj |
| .. section: Documentation |
| |
| Document missing public :class:`wave.Wave_write` getter methods. |
| |
| .. |
| |
| .. date: 2026-01-06-16-04-08 |
| .. gh-issue: 110937 |
| .. nonce: SyO5lk |
| .. section: Documentation |
| |
| Document rest of full public :class:`importlib.metadata.Distribution` API. |
| Also add the (already documented) :class:`~importlib.metadata.PackagePath` |
| to ``__all__``. |
| |
| .. |
| |
| .. date: 2025-08-02-18-59-01 |
| .. gh-issue: 136246 |
| .. nonce: RIK7nE |
| .. section: Documentation |
| |
| A new "Improve this page" link is available in the left-hand sidebar of the |
| docs, offering links to create GitHub issues, discussion forum posts, or |
| pull requests. |
| |
| .. |
| |
| .. date: 2026-03-09-18-52-03 |
| .. gh-issue: 145701 |
| .. nonce: 79KQyO |
| .. section: Core and Builtins |
| |
| Fix :exc:`SystemError` when ``__classdict__`` or |
| ``__conditional_annotations__`` is in a class-scope inlined comprehension. |
| Found by OSS Fuzz in :oss-fuzz:`491105000`. |
| |
| .. |
| |
| .. date: 2026-03-06-21-05-05 |
| .. gh-issue: 145615 |
| .. nonce: NKXXZgDW |
| .. section: Core and Builtins |
| |
| Fixed a memory leak in the :term:`free-threaded build` where mimalloc pages |
| could become permanently unreclaimable until the owning thread exited. |
| |
| .. |
| |
| .. date: 2026-03-06-01-36-20 |
| .. gh-issue: 116738 |
| .. nonce: OWVWRx |
| .. section: Core and Builtins |
| |
| Make :meth:`!mmap.mmap.set_name` thread-safe on the :term:`free threaded |
| <free threading>` build. |
| |
| .. |
| |
| .. date: 2026-03-05-19-10-56 |
| .. gh-issue: 145566 |
| .. nonce: H4RupyYN |
| .. section: Core and Builtins |
| |
| In the free threading build, skip the stop-the-world pause when reassigning |
| ``__class__`` on a newly created object. |
| |
| .. |
| |
| .. date: 2026-03-05-16-16-17 |
| .. gh-issue: 143055 |
| .. nonce: qDUFlY |
| .. section: Core and Builtins |
| |
| Fix crash in AST unparser when unparsing dict comprehension unpacking. Found |
| by OSS Fuzz in :oss-fuzz:`489790200`. |
| |
| .. |
| |
| .. date: 2026-03-01-13-37-31 |
| .. gh-issue: 145335 |
| .. nonce: e36kPJ |
| .. section: Core and Builtins |
| |
| Fix a crash in :func:`os.pathconf` when called with ``-1`` as the path |
| argument. |
| |
| .. |
| |
| .. date: 2026-02-28-16-46-17 |
| .. gh-issue: 145376 |
| .. nonce: lG5u1a |
| .. section: Core and Builtins |
| |
| Fix reference leaks in various unusual error scenarios. |
| |
| .. |
| |
| .. date: 2026-02-26-21-36-00 |
| .. gh-issue: 145234 |
| .. nonce: w0mQ9n |
| .. section: Core and Builtins |
| |
| Fixed a ``SystemError`` in the parser when an encoding cookie (for example, |
| UTF-7) decodes to carriage returns (``\r``). Newlines are now normalized |
| after decoding in the string tokenizer. |
| |
| Patch by Pablo Galindo. |
| |
| .. |
| |
| .. date: 2026-02-26-21-07-38 |
| .. gh-issue: 145275 |
| .. nonce: qE-3O1 |
| .. section: Core and Builtins |
| |
| Added the :option:`-X pathconfig_warnings<-X>` and |
| :envvar:`PYTHON_PATHCONFIG_WARNINGS` options, allowing to disable warnings |
| from :ref:`sys-path-init`. |
| |
| .. |
| |
| .. date: 2026-02-26-20-51-54 |
| .. gh-issue: 145273 |
| .. nonce: B5QcUp |
| .. section: Core and Builtins |
| |
| A warning is now shown during :ref:`sys-path-init` if it can't find a valid |
| standard library. |
| |
| .. |
| |
| .. date: 2026-02-26-18-00-00 |
| .. gh-issue: 145241 |
| .. nonce: hL2k9Q |
| .. section: Core and Builtins |
| |
| Specialized the parser error for when ``with`` items are followed by a |
| trailing comma (for example, ``with item,:``), raising a clearer |
| :exc:`SyntaxError` message. Patch by Pablo Galindo and Bartosz Sławecki. |
| |
| .. |
| |
| .. date: 2026-02-26-12-00-00 |
| .. gh-issue: 130555 |
| .. nonce: TMSOIu |
| .. section: Core and Builtins |
| |
| Fix use-after-free in :meth:`dict.clear` when the dictionary values are |
| embedded in an object and a destructor causes re-entrant mutation of the |
| dictionary. |
| |
| .. |
| |
| .. date: 2026-02-25-15-02-08 |
| .. gh-issue: 145197 |
| .. nonce: G6hAUk |
| .. section: Core and Builtins |
| |
| Fix JIT trace crash when recording function from cleared generator frame. |
| |
| .. |
| |
| .. date: 2026-02-24-18-30-56 |
| .. gh-issue: 145187 |
| .. nonce: YjPu1Z |
| .. section: Core and Builtins |
| |
| Fix compiler assertion fail when a type parameter bound contains an invalid |
| expression in a conditional block. |
| |
| .. |
| |
| .. date: 2026-02-23-23-18-28 |
| .. gh-issue: 145142 |
| .. nonce: T-XbVe |
| .. section: Core and Builtins |
| |
| Fix a crash in the free-threaded build when the dictionary argument to |
| :meth:`str.maketrans` is concurrently modified. |
| |
| .. |
| |
| .. date: 2026-02-22-22-05-09 |
| .. gh-issue: 145118 |
| .. nonce: TaKMJE |
| .. section: Core and Builtins |
| |
| :meth:`str.maketrans` now accepts :class:`frozendict`. |
| |
| .. |
| |
| .. date: 2026-02-22-20-15-00 |
| .. gh-issue: 144015 |
| .. nonce: pystrhex_simd |
| .. section: Core and Builtins |
| |
| Speed up :meth:`bytes.hex`, :meth:`bytearray.hex`, :func:`binascii.hexlify`, |
| and :mod:`hashlib` ``.hexdigest()`` operations with SIMD on x86-64, ARM64, |
| and ARM32 with NEON when built with gcc (version 12 or higher) or clang |
| (version 3 or higher) compilers. Around 1.1-3x faster for common 16-64 byte |
| inputs such as hashlib hex digests, and up to 8x faster for larger data. |
| |
| .. |
| |
| .. date: 2026-02-22-19-05-03 |
| .. gh-issue: 145118 |
| .. nonce: bU6Sic |
| .. section: Core and Builtins |
| |
| :func:`type` now accepts :class:`frozendict` as an argument. |
| |
| .. |
| |
| .. date: 2026-02-22-07-51-10 |
| .. gh-issue: 145064 |
| .. nonce: iIMGKA |
| .. section: Core and Builtins |
| |
| Fix JIT optimizer assertion failure during ``CALL_ALLOC_AND_ENTER_INIT`` |
| side exit. |
| |
| .. |
| |
| .. date: 2026-02-21-12-16-46 |
| .. gh-issue: 145055 |
| .. nonce: VyT-zI |
| .. section: Core and Builtins |
| |
| :func:`exec` and :func:`eval` now accept :class:`frozendict` for *globals*. |
| Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-21-09-47-45 |
| .. gh-issue: 145058 |
| .. nonce: e-RBw- |
| .. section: Core and Builtins |
| |
| Fix a crash when :func:`!__lazy_import__` is passed a non-string argument, |
| by raising an :exc:`TypeError` instead. |
| |
| .. |
| |
| .. date: 2026-02-19-12-49-15 |
| .. gh-issue: 144995 |
| .. nonce: Ob2oYJ |
| .. section: Core and Builtins |
| |
| Optimize :class:`memoryview` comparison: a :class:`memoryview` is equal to |
| itself, there is no need to compare values. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-18-21-44-39 |
| .. gh-issue: 141510 |
| .. nonce: 7LST2O |
| .. section: Core and Builtins |
| |
| Update specializer to support frozendict. Patch by Donghee Na. |
| |
| .. |
| |
| .. date: 2026-02-17-22-27-11 |
| .. gh-issue: 141510 |
| .. nonce: -4yYsf |
| .. section: Core and Builtins |
| |
| Optimize :meth:`!frozendict.fromkeys` to avoid unnecessary thread-safety |
| operations in frozendict cases. Patch by Donghee Na. |
| |
| .. |
| |
| .. date: 2026-02-17-21-04-03 |
| .. gh-issue: 100239 |
| .. nonce: LyVabQ |
| .. section: Core and Builtins |
| |
| Speedup ``BINARY_OP_EXTEND`` for exact floats and medium-size integers by up |
| to 15%. Patch by Chris Eibl. |
| |
| .. |
| |
| .. date: 2026-02-17-18-27-28 |
| .. gh-issue: 144914 |
| .. nonce: DcXO4m |
| .. section: Core and Builtins |
| |
| Use ``mimalloc`` for raw memory allocations such as via |
| :c:func:`PyMem_RawMalloc` for better performance on :term:`free-threaded |
| builds <free-threaded build>`. Patch by Kumar Aditya. |
| |
| .. |
| |
| .. date: 2026-02-16-12-28-43 |
| .. gh-issue: 144872 |
| .. nonce: k9_Q30 |
| .. section: Core and Builtins |
| |
| Fix heap buffer overflow in the parser found by OSS-Fuzz. |
| |
| .. |
| |
| .. date: 2026-02-13-18-30-59 |
| .. gh-issue: 144766 |
| .. nonce: JGu3x3 |
| .. section: Core and Builtins |
| |
| Fix a crash in fork child process when perf support is enabled. |
| |
| .. |
| |
| .. date: 2026-02-13-12-00-00 |
| .. gh-issue: 144759 |
| .. nonce: d3qYpe |
| .. section: Core and Builtins |
| |
| Fix undefined behavior in the lexer when ``start`` and ``multi_line_start`` |
| pointers are ``NULL`` in ``_PyLexer_remember_fstring_buffers()`` and |
| ``_PyLexer_restore_fstring_buffers()``. The ``NULL`` pointer arithmetic |
| (``NULL - valid_pointer``) is now guarded with explicit ``NULL`` checks. |
| |
| .. |
| |
| .. date: 2026-02-12-19-01-13 |
| .. gh-issue: 141510 |
| .. nonce: KlKjZg |
| .. section: Core and Builtins |
| |
| Add built-in :class:`frozendict` type. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-12-12-39-50 |
| .. gh-issue: 144681 |
| .. nonce: Ns2OT2 |
| .. section: Core and Builtins |
| |
| Fix a JIT assertion failure when a conditional branch jumps to the same |
| target as the fallthrough path. |
| |
| .. |
| |
| .. date: 2026-02-11-13-30-11 |
| .. gh-issue: 143300 |
| .. nonce: yjB63- |
| .. section: Core and Builtins |
| |
| Add :c:func:`PyUnstable_SetImmortal` C-API function to mark objects as |
| :term:`immortal`. |
| |
| .. |
| |
| .. date: 2026-02-11-11-28-25 |
| .. gh-issue: 144702 |
| .. nonce: XjFumv |
| .. section: Core and Builtins |
| |
| Clarify the error message raised when a class pattern is used to match on a |
| non-class object. |
| |
| .. |
| |
| .. date: 2026-02-08-13-14-00 |
| .. gh-issue: 144569 |
| .. nonce: pjlJVe |
| .. section: Core and Builtins |
| |
| Optimize ``BINARY_SLICE`` for list, tuple, and unicode by avoiding temporary |
| ``slice`` object creation. |
| |
| .. |
| |
| .. date: 2026-02-06-21-45-52 |
| .. gh-issue: 144438 |
| .. nonce: GI_uB1LR |
| .. section: Core and Builtins |
| |
| Align the QSBR thread state array to a 64-byte cache line boundary to avoid |
| false sharing in the :term:`free-threaded build`. |
| |
| .. |
| |
| .. date: 2025-12-06-15-46-32 |
| .. gh-issue: 142349 |
| .. nonce: IdTuYL |
| .. section: Core and Builtins |
| |
| Implement :pep:`810`. Patch by Pablo Galindo and Dino Viehland. |
| |
| .. |
| |
| .. date: 2025-11-09-15-44-58 |
| .. gh-issue: 141226 |
| .. nonce: KTb_3F |
| .. section: Core and Builtins |
| |
| Deprecate :pep:`456` support for providing an external definition of the |
| string hashing scheme. Removal is scheduled for Python 3.19. Patch by |
| Bénédikt Tran. |
| |
| .. |
| |
| .. date: 2025-09-15-13-28-48 |
| .. gh-issue: 138912 |
| .. nonce: 61EYbn |
| .. section: Core and Builtins |
| |
| Improve :opcode:`MATCH_CLASS` performance by up to 52% in certain cases. |
| Patch by Marc Mueller. |
| |
| .. |
| |
| .. date: 2025-02-19-21-06-30 |
| .. gh-issue: 130327 |
| .. nonce: z3TaR8 |
| .. section: Core and Builtins |
| |
| Fix erroneous clearing of an object's :attr:`~object.__dict__` if |
| overwritten at runtime. |
| |
| .. |
| |
| .. date: 2023-07-26-00-03-00 |
| .. gh-issue: 80667 |
| .. nonce: N7Dh8B |
| .. section: Core and Builtins |
| |
| Literals using the ``\N{name}`` escape syntax can now construct CJK |
| ideographs and Hangul syllables using case-insensitive names. |
| |
| .. |
| |
| .. date: 2026-03-03-14-59-57 |
| .. gh-issue: 142417 |
| .. nonce: HiNP5j |
| .. section: C API |
| |
| Restore private provisional ``_Py_InitializeMain()`` function removed in |
| Python 3.14. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-24-14-46-05 |
| .. gh-issue: 144748 |
| .. nonce: uhnFtE |
| .. section: C API |
| |
| :c:func:`PyErr_CheckSignals` now raises the exception scheduled by |
| :c:func:`PyThreadState_SetAsyncExc`, if any. |
| |
| .. |
| |
| .. date: 2026-02-18-15-12-34 |
| .. gh-issue: 144981 |
| .. nonce: 4ZdM63 |
| .. section: C API |
| |
| Made :c:func:`PyUnstable_Code_SetExtra`, :c:func:`PyUnstable_Code_GetExtra`, |
| and :c:func:`PyUnstable_Eval_RequestCodeExtraIndex` thread-safe on the |
| :term:`free threaded <free threading>` build. |
| |
| .. |
| |
| .. date: 2026-02-12-19-03-31 |
| .. gh-issue: 141510 |
| .. nonce: U_1tjz |
| .. section: C API |
| |
| Add the following functions for the new :class:`frozendict` type: |
| |
| * :c:func:`PyAnyDict_Check` |
| * :c:func:`PyAnyDict_CheckExact` |
| * :c:func:`PyFrozenDict_Check` |
| * :c:func:`PyFrozenDict_CheckExact` |
| * :c:func:`PyFrozenDict_New` |
| |
| Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-10-14-49-49 |
| .. gh-issue: 121617 |
| .. nonce: 57vMqa |
| .. section: C API |
| |
| ``Python.h`` now also includes ``<string.h>`` in the limited C API version |
| 3.11 and newer to fix the :c:macro:`Py_CLEAR` macro which uses ``memcpy()``. |
| Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-01-27-18-15-15 |
| .. gh-issue: 144175 |
| .. nonce: qHK5Jf |
| .. section: C API |
| |
| Add :c:func:`PyArg_ParseArray` and :c:func:`PyArg_ParseArrayAndKeywords` |
| functions to parse arguments of functions using the :c:macro:`METH_FASTCALL` |
| calling convention. Patch by Victor Stinner. |
| |
| .. |
| |
| .. date: 2026-02-27-18-10-02 |
| .. gh-issue: 144533 |
| .. nonce: 21fk9L |
| .. section: Build |
| |
| Use wasmtime's ``--argv0`` to auto-discover sysconfig in WASI builds |
| |
| .. |
| |
| .. date: 2026-02-22-13-35-20 |
| .. gh-issue: 145110 |
| .. nonce: KgWofW |
| .. section: Build |
| |
| Fix targets "Clean" and "CLeanAll" in case of PGO builds on Windows. Patch |
| by Chris Eibl. |
| |
| .. |
| |
| .. date: 2026-02-10-18-26-04 |
| .. gh-issue: 144679 |
| .. nonce: FIH73W |
| .. section: Build |
| |
| When building with Visual Studio 2026 (Version 18), use PlatformToolSet v145 |
| by default. Patch by Chris Eibl. |
| |
| .. |
| |
| .. date: 2026-02-10-16-59-56 |
| .. gh-issue: 144675 |
| .. nonce: Wrf3Es |
| .. section: Build |
| |
| Update to WASI SDK 30. |
| |
| .. |
| |
| .. date: 2025-07-21-00-33-38 |
| .. gh-issue: 136677 |
| .. nonce: Y1_3ec |
| .. section: Build |
| |
| Introduce executable specific linker flags to ``./configure``. |
