* :ref:`PEP 750: Template strings <whatsnew314-pep750>`
* :ref:`PEP 758: Allow except and except* expressions without parentheses <whatsnew314-pep758>`
* :ref:`PEP 761: Discontinuation of PGP signatures <whatsnew314-no-more-pgp>`
-* :ref:`PEP 765: Disallow return/break/continue that exit a finally block <whatsnew314-pep765>`
+* :ref:`PEP 765: Disallow return/break/continue that exit a finally block <whatsnew314-finally-syntaxwarning>`
* :ref:`Free-threaded mode improvements <whatsnew314-free-threaded-cpython>`
* :ref:`PEP 768: Safe external debugger interface for CPython <whatsnew314-pep768>`
* :ref:`PEP 784: Adding Zstandard to the standard library <whatsnew314-pep784>`
* :ref:`A new type of interpreter <whatsnew314-tail-call>`
-* :ref:`Syntax highlighting in PyREPL <whatsnew314-pyrepl-highlighting>`,
+* :ref:`Syntax highlighting in the default interactive shell <whatsnew314-pyrepl-highlighting>`,
and color output in :ref:`unittest <whatsnew314-color-unittest>`,
:ref:`argparse <whatsnew314-color-argparse>`,
:ref:`json <whatsnew314-color-json>` and
* :ref:`Binary releases for the experimental just-in-time compiler <whatsnew314-jit-compiler>`
-Incompatible changes
-====================
-
-On platforms other than macOS and Windows, the default :ref:`start
-method <multiprocessing-start-methods>` for :mod:`multiprocessing`
-and :class:`~concurrent.futures.ProcessPoolExecutor` switches from
-*fork* to *forkserver*.
-
-See :ref:`(1) <whatsnew314-concurrent-futures-start-method>` and
-:ref:`(2) <whatsnew314-multiprocessing-start-method>` for details.
-
-If you encounter :exc:`NameError`\s or pickling errors coming out of
-:mod:`multiprocessing` or :mod:`concurrent.futures`, see the
-:ref:`forkserver restrictions <multiprocessing-programming-forkserver>`.
-
-The interpreter avoids some reference count modifications internally when
-it's safe to do so. This can lead to different values returned from
-:func:`sys.getrefcount` and :c:func:`Py_REFCNT` compared to previous versions
-of Python. See :ref:`below <whatsnew314-refcount>` for details.
New features
============
~^^^
TypeError: cannot use 'list' as a dict key (unhashable type: 'list')
+* Improved error message when an object supporting the synchronous
+ context manager protocol is entered using :keyword:`async with`
+ instead of :keyword:`with`,
+ and vice versa for the asynchronous context manager protocol.
+ (Contributed by Bénédikt Tran in :gh:`128398`.)
+
.. _whatsnew314-pep741:
context manager.
-.. _whatsnew314-pyrepl-highlighting:
-
-Syntax highlighting in PyREPL
------------------------------
-
-The default :term:`interactive` shell now highlights Python syntax as you
-type. The feature is enabled by default unless the
-:envvar:`PYTHON_BASIC_REPL` environment is set or any color-disabling
-environment variables are used. See :ref:`using-on-controlling-color` for
-details.
-
-The default color theme for syntax highlighting strives for good contrast
-and uses exclusively the 4-bit VGA standard ANSI color codes for maximum
-compatibility. The theme can be customized using an experimental API
-``_colorize.set_theme()``. This can be called interactively, as well as
-in the :envvar:`PYTHONSTARTUP` script.
-
-(Contributed by Łukasz Langa in :gh:`131507`.)
-
-
.. _whatsnew314-jit-compiler:
Binary releases for the experimental just-in-time compiler
(Contributed by Neil Schemenauer and Kumar Aditya in :gh:`130010`.)
-.. _whatsnew314-incremental-gc:
-
-Incremental garbage collection
-------------------------------
-
-The cycle garbage collector is now incremental.
-This means that maximum pause times are reduced
-by an order of magnitude or more for larger heaps.
-
-There are now only two generations: young and old.
-When :func:`gc.collect` is not called directly, the
-GC is invoked a little less frequently. When invoked, it
-collects the young generation and an increment of the
-old generation, instead of collecting one or more generations.
-
-The behavior of :func:`!gc.collect` changes slightly:
-
-* ``gc.collect(1)``: Performs an increment of garbage collection,
- rather than collecting generation 1.
-* Other calls to :func:`!gc.collect` are unchanged.
-
-(Contributed by Mark Shannon in :gh:`108362`.)
Platform support
================
:pep:`tier 3 <11#tier-3>`. As a part of this effort, more than 25 bugs in
`Emscripten libc`__ were fixed. Emscripten now includes support
for :mod:`ctypes`, :mod:`termios`, and :mod:`fcntl`, as well as
- experimental support for :ref:`PyREPL <tut-interactive>`.
+ experimental support for the new :ref:`default interactive shell
+ <tut-interactive>`.
(Contributed by R. Hood Chatham in :gh:`127146`, :gh:`127683`, and :gh:`136931`.)
__ https://emscripten.org/docs/porting/emscripten-runtime-environment.html
+* iOS and macOS apps can now be configured to redirect ``stdout`` and
+ ``stderr`` content to the system log.
+ (Contributed by Russell Keith-Magee in :gh:`127592`.)
+
+* The iOS testbed is now able to stream test output while the test is running.
+ The testbed can also be used to run the test suite of projects other than
+ CPython itself.
+ (Contributed by Russell Keith-Magee in :gh:`127592`.)
+
+
Other language changes
======================
-* The default :term:`interactive` shell now supports import autocompletion.
- This means that typing ``import foo`` and pressing ``<tab>`` will suggest
- modules starting with ``foo``. Similarly, typing ``from foo import b`` will
- suggest submodules of ``foo`` starting with ``b``. Note that autocompletion
- of module attributes is not currently supported.
- (Contributed by Tomas Roun in :gh:`69605`.)
-
-* The :func:`map` built-in now has an optional keyword-only *strict* flag
- like :func:`zip` to check that all the iterables are of equal length.
- (Contributed by Wannes Boeykens in :gh:`119793`.)
+* All Windows code pages are now supported as 'cpXXX' codecs on Windows.
+ (Contributed by Serhiy Storchaka in :gh:`123803`.)
-* Incorrect usage of :keyword:`await` and asynchronous comprehensions
- is now detected even if the code is optimized away by the :option:`-O`
- command-line option. For example, ``python -O -c 'assert await 1'``
- now produces a :exc:`SyntaxError`. (Contributed by Jelle Zijlstra in :gh:`121637`.)
+* Implement mixed-mode arithmetic rules combining real and complex numbers
+ as specified by the C standard since C99.
+ (Contributed by Sergey B Kirpichev in :gh:`69639`.)
-* Writes to ``__debug__`` are now detected even if the code is optimized
- away by the :option:`-O` command-line option. For example,
- ``python -O -c 'assert (__debug__ := 1)'`` now produces a
- :exc:`SyntaxError`. (Contributed by Irit Katriel in :gh:`122245`.)
+* More syntax errors are now detected regardless of optimisation and
+ the :option:`-O` command-line option.
+ This includes writes to ``__debug__``, incorrect use of :keyword:`await`,
+ and asynchronous comprehensions outside asynchronous functions.
+ For example, ``python -O -c 'assert (__debug__ := 1)'``
+ or ``python -O -c 'assert await 1'`` now produce :exc:`SyntaxError`\ s.
+ (Contributed by Irit Katriel and Jelle Zijlstra in :gh:`122245` & :gh:`121637`.)
-* Add class methods :meth:`float.from_number` and :meth:`complex.from_number`
- to convert a number to :class:`float` or :class:`complex` type correspondingly.
- They raise an error if the argument is a string.
- (Contributed by Serhiy Storchaka in :gh:`84978`.)
+* When subclassing a pure C type, the C slots for the new type
+ are no longer replaced with a wrapped version on class creation
+ if they are not explicitly overridden in the subclass.
+ (Contributed by Tomasz Pytel in :gh:`132284`.)
-* Implement mixed-mode arithmetic rules combining real and complex numbers as
- specified by C standards since C99.
- (Contributed by Sergey B Kirpichev in :gh:`69639`.)
-* All Windows code pages are now supported as "cpXXX" codecs on Windows.
- (Contributed by Serhiy Storchaka in :gh:`123803`.)
+Built-ins
+---------
-* :class:`super` objects are now :mod:`pickleable <pickle>` and
- :mod:`copyable <copy>`.
- (Contributed by Serhiy Storchaka in :gh:`125767`.)
+* The :meth:`bytes.fromhex` and :meth:`bytearray.fromhex` methods now accept
+ ASCII :class:`bytes` and :term:`bytes-like objects <bytes-like object>`.
+ (Contributed by Daniel Pope in :gh:`129349`.)
-* The :class:`memoryview` type now supports subscription,
- making it a :term:`generic type`.
- (Contributed by Brian Schubert in :gh:`126012`.)
+* Add class methods :meth:`float.from_number` and :meth:`complex.from_number`
+ to convert a number to :class:`float` or :class:`complex` type correspondingly.
+ They raise a :exc:`TypeError` if the argument is not a real number.
+ (Contributed by Serhiy Storchaka in :gh:`84978`.)
* Support underscore and comma as thousands separators in the fractional part
for floating-point presentation types of the new-style string formatting
(with :func:`format` or :ref:`f-strings`).
(Contributed by Sergey B Kirpichev in :gh:`87790`.)
-* The :func:`bytes.fromhex` and :func:`bytearray.fromhex` methods now accept
- ASCII :class:`bytes` and :term:`bytes-like objects <bytes-like object>`.
- (Contributed by Daniel Pope in :gh:`129349`.)
-
-* Support ``\z`` as a synonym for ``\Z`` in :mod:`regular expressions <re>`.
- It is interpreted unambiguously in many other regular expression engines,
- unlike ``\Z``, which has subtly different behavior.
- (Contributed by Serhiy Storchaka in :gh:`133306`.)
+* The :func:`int` function no longer delegates to :meth:`~object.__trunc__`.
+ Classes that want to support conversion to :func:`!int` must implement
+ either :meth:`~object.__int__` or :meth:`~object.__index__`.
+ (Contributed by Mark Dickinson in :gh:`119743`.)
-* ``\B`` in :mod:`regular expression <re>` now matches the empty input string.
- Now it is always the opposite of ``\b``.
- (Contributed by Serhiy Storchaka in :gh:`124130`.)
+* The :func:`map` function now has an optional keyword-only *strict* flag
+ like :func:`zip` to check that all the iterables are of equal length.
+ (Contributed by Wannes Boeykens in :gh:`119793`.)
-* iOS and macOS apps can now be configured to redirect ``stdout`` and
- ``stderr`` content to the system log. (Contributed by Russell Keith-Magee in
- :gh:`127592`.)
+* The :class:`memoryview` type now supports subscription,
+ making it a :term:`generic type`.
+ (Contributed by Brian Schubert in :gh:`126012`.)
-* The iOS testbed is now able to stream test output while the test is running.
- The testbed can also be used to run the test suite of projects other than
- CPython itself. (Contributed by Russell Keith-Magee in :gh:`127592`.)
+* Using :data:`NotImplemented` in a boolean context
+ will now raise a :exc:`TypeError`.
+ This has raised a :exc:`DeprecationWarning` since Python 3.9.
+ (Contributed by Jelle Zijlstra in :gh:`118767`.)
-* Three-argument :func:`pow` now tries calling :meth:`~object.__rpow__` if
- necessary. Previously it was only called in two-argument :func:`!pow` and the
- binary power operator.
+* Three-argument :func:`pow` now tries calling :meth:`~object.__rpow__`
+ if necessary.
+ Previously it was only called in two-argument :func:`!pow`
+ and the binary power operator.
(Contributed by Serhiy Storchaka in :gh:`130104`.)
-* Add a built-in implementation for HMAC (:rfc:`2104`) using formally verified
- code from the `HACL* <https://github.com/hacl-star/hacl-star/>`__ project.
- This implementation is used as a fallback when the OpenSSL implementation
- of HMAC is not available.
- (Contributed by Bénédikt Tran in :gh:`99108`.)
+* :class:`super` objects are now :mod:`copyable <copy>` and :mod:`pickleable
+ <pickle>`.
+ (Contributed by Serhiy Storchaka in :gh:`125767`.)
+
+
+Command line and environment
+----------------------------
* The import time flag can now track modules that are already loaded ('cached'),
via the new :option:`-X importtime=2 <-X>`.
When such a module is imported, the ``self`` and ``cumulative`` times
are replaced by the string ``cached``.
+
Values above ``2`` for ``-X importtime`` are now reserved for future use.
- (Contributed by Noah Kim and Adam Turner in :gh:`118655`.)
-* When subclassing from a pure C type, the C slots for the new type are no
- longer replaced with a wrapped version on class creation if they are not
- explicitly overridden in the subclass.
- (Contributed by Tomasz Pytel in :gh:`132329`.)
+ (Contributed by Noah Kim and Adam Turner in :gh:`118655`.)
* The command-line option :option:`-c` now automatically dedents its code
argument before execution. The auto-dedentation behavior mirrors
:func:`textwrap.dedent`.
(Contributed by Jon Crall and Steven Sun in :gh:`103998`.)
-* Improve error message when an object supporting the synchronous
- context manager protocol is entered using :keyword:`async
- with` instead of :keyword:`with`.
- And vice versa with the asynchronous context manager protocol.
- (Contributed by Bénédikt Tran in :gh:`128398`.)
-
* :option:`!-J` is no longer a reserved flag for Jython_,
and now has no special meaning.
(Contributed by Adam Turner in :gh:`133336`.)
.. _Jython: https://www.jython.org/
-* The :func:`int` built-in no longer delegates to :meth:`~object.__trunc__`.
- Classes that want to support conversion to :func:`!int` must implement
- either :meth:`~object.__int__` or :meth:`~object.__index__`.
- (Contributed by Mark Dickinson in :gh:`119743`.)
-* Using :data:`NotImplemented` in a boolean context
- will now raise a :exc:`TypeError`.
- This has raised a :exc:`DeprecationWarning` since Python 3.9.
- (Contributed by Jelle Zijlstra in :gh:`118767`.)
+.. _whatsnew314-finally-syntaxwarning:
+PEP 765: Control flow in :keyword:`finally` blocks
+--------------------------------------------------
-.. _whatsnew314-pep765:
+The compiler now emits a :exc:`SyntaxWarning` when a :keyword:`return`,
+:keyword:`break`, or :keyword:`continue` statement have the effect of
+leaving a :keyword:`finally` block.
+This change is specified in :pep:`765`.
-PEP 765: Disallow ``return``/``break``/``continue`` that exit a ``finally`` block
----------------------------------------------------------------------------------
+(Contributed by Irit Katriel in :gh:`130080`.)
-The compiler emits a :exc:`SyntaxWarning` when a :keyword:`return`, :keyword:`break` or
-:keyword:`continue` statement appears where it exits a :keyword:`finally` block.
-This change is specified in :pep:`765`.
+
+.. _whatsnew314-incremental-gc:
+
+Incremental garbage collection
+------------------------------
+
+The cycle garbage collector is now incremental.
+This means that maximum pause times are reduced
+by an order of magnitude or more for larger heaps.
+
+There are now only two generations: young and old.
+When :func:`gc.collect` is not called directly, the
+GC is invoked a little less frequently. When invoked, it
+collects the young generation and an increment of the
+old generation, instead of collecting one or more generations.
+
+The behavior of :func:`!gc.collect` changes slightly:
+
+* ``gc.collect(1)``: Performs an increment of garbage collection,
+ rather than collecting generation 1.
+* Other calls to :func:`!gc.collect` are unchanged.
+
+(Contributed by Mark Shannon in :gh:`108362`.)
+
+
+Default interactive shell
+-------------------------
+
+.. _whatsnew314-pyrepl-highlighting:
+
+* The default :term:`interactive` shell now highlights Python syntax.
+ The feature is enabled by default, save if :envvar:`PYTHON_BASIC_REPL`
+ or any other environment variable that disables colour is set.
+ See :ref:`using-on-controlling-color` for details.
+
+ The default color theme for syntax highlighting strives for good contrast
+ and exclusively uses the 4-bit VGA standard ANSI color codes for maximum
+ compatibility. The theme can be customized using an experimental API
+ :func:`!_colorize.set_theme`.
+ This can be called interactively or in the :envvar:`PYTHONSTARTUP` script.
+ Note that this function has no stability guarantees,
+ and may change or be removed.
+
+ (Contributed by Łukasz Langa in :gh:`131507`.)
+
+* The default :term:`interactive` shell now supports import auto-completion.
+ This means that typing ``import co`` and pressing :kbd:`<Tab>` will suggest
+ modules starting with ``co``. Similarly, typing ``from concurrent import i``
+ will suggest submodules of ``concurrent`` starting with ``i``.
+ Note that autocompletion of module attributes is not currently supported.
+ (Contributed by Tomas Roun in :gh:`69605`.)
New modules
.. _whatsnew314-concurrent-futures-start-method:
-* The default :class:`~concurrent.futures.ProcessPoolExecutor`
- :ref:`start method <multiprocessing-start-methods>` changed
- from :ref:`fork <multiprocessing-start-method-fork>` to :ref:`forkserver
- <multiprocessing-start-method-forkserver>` on platforms other than macOS and
- Windows where it was already :ref:`spawn <multiprocessing-start-method-spawn>`.
+* On Unix platforms other than macOS, :ref:`'forkserver'
+ <multiprocessing-start-method-forkserver>` is now the the default :ref:`start
+ method <multiprocessing-start-methods>` for
+ :class:`~concurrent.futures.ProcessPoolExecutor`
+ (replacing :ref:`'fork' <multiprocessing-start-method-fork>`).
+ This change does not affect Windows or macOS, where :ref:`'spawn'
+ <multiprocessing-start-method-spawn>` remains the default start method.
If the threading incompatible *fork* method is required, you must explicitly
request it by supplying a multiprocessing context *mp_context* to
* Add a built-in implementation for HMAC (:rfc:`2104`) using formally verified
code from the `HACL* <https://github.com/hacl-star/hacl-star/>`__ project.
+ This implementation is used as a fallback when the OpenSSL implementation
+ of HMAC is not available.
(Contributed by Bénédikt Tran in :gh:`99108`.)
.. _whatsnew314-multiprocessing-start-method:
-* The default :ref:`start method <multiprocessing-start-methods>` changed
- from :ref:`fork <multiprocessing-start-method-fork>` to :ref:`forkserver
- <multiprocessing-start-method-forkserver>` on platforms other than macOS and
- Windows where it was already :ref:`spawn <multiprocessing-start-method-spawn>`.
+* On Unix platforms other than macOS, :ref:`'forkserver'
+ <multiprocessing-start-method-forkserver>` is now the the default :ref:`start
+ method <multiprocessing-start-methods>`
+ (replacing :ref:`'fork' <multiprocessing-start-method-fork>`).
+ This change does not affect Windows or macOS, where :ref:`'spawn'
+ <multiprocessing-start-method-spawn>` remains the default start method.
If the threading incompatible *fork* method is required, you must explicitly
request it via a context from :func:`multiprocessing.get_context` (preferred)
(Contributed by Tian Gao in :gh:`132576`.)
* Source code displayed in :mod:`pdb` will be syntax-highlighted. This feature
- can be controlled using the same methods as PyREPL, in addition to the newly
- added ``colorize`` argument of :class:`pdb.Pdb`.
+ can be controlled using the same methods as the default :term:`interactive`
+ shell, in addition to the newly added ``colorize`` argument of :class:`pdb.Pdb`.
(Contributed by Tian Gao and Łukasz Langa in :gh:`133355`.)
(Contributed by Jelle Zijlstra in :gh:`101552`.)
+re
+--
+
+* Support ``\z`` as a synonym for ``\Z`` in :mod:`regular expressions <re>`.
+ It is interpreted unambiguously in many other regular expression engines,
+ unlike ``\Z``, which has subtly different behavior.
+ (Contributed by Serhiy Storchaka in :gh:`133306`.)
+
+* ``\B`` in :mod:`regular expression <re>` now matches the empty input string.
+ Now it is always the opposite of ``\b``.
+ (Contributed by Serhiy Storchaka in :gh:`124130`.)
+
+
socket
------
(Contributed by Adam Turner, Bénédikt Tran, Chris Markiewicz, Eli Schwartz,
Hugo van Kemenade, Jelle Zijlstra, and others in :gh:`118761`.)
+* The interpreter avoids some reference count modifications internally when
+ it's safe to do so. This can lead to different values returned from
+ :func:`sys.getrefcount` and :c:func:`Py_REFCNT` compared to previous versions
+ of Python. See :ref:`below <whatsnew314-refcount>` for details.
+
asyncio
-------
Changes in the Python API
-------------------------
+* On Unix platforms other than macOS, *forkserver* is now the default
+ :ref:`start method <multiprocessing-start-methods>` for :mod:`multiprocessing`
+ and :class:`~concurrent.futures.ProcessPoolExecutor`, instead of *fork*.
+
+ See :ref:`(1) <whatsnew314-concurrent-futures-start-method>` and
+ :ref:`(2) <whatsnew314-multiprocessing-start-method>` for details.
+
+ If you encounter :exc:`NameError`\s or pickling errors coming out of
+ :mod:`multiprocessing` or :mod:`concurrent.futures`, see the
+ :ref:`forkserver restrictions <multiprocessing-programming-forkserver>`.
+
+ This change does not affect Windows or macOS, where :ref:`'spawn'
+ <multiprocessing-start-method-spawn>` remains the default start method.
+
* :class:`functools.partial` is now a method descriptor.
Wrap it in :func:`staticmethod` if you want to preserve the old behavior.
(Contributed by Serhiy Storchaka and Dominykas Grigonis in :gh:`121027`.)
projects / thirdparty / Python / cpython.git / commitdiff
