mirror of https://github.com/python/cpython
[3.13] GH-109975: Copyedit 3.13 What's New: Other Language Changes (GH-123086) (#123101)
GH-109975: Copyedit 3.13 What's New: Other Language Changes (GH-123086)
(cherry picked from commit d60b97a833)
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
This commit is contained in:
Miss Islington (bot)
GitHub
parent
8d95102447
commit
6001deacb7
|
|
@ -242,6 +242,7 @@ Windows support contributed by Dino Viehland and Anthony Shaw.)
|
|||
|
||||
.. _`PyPy project`: https://pypy.org/
|
||||
|
||||
|
||||
.. _whatsnew313-improved-error-messages:
|
||||
|
||||
Improved error messages
|
||||
|
|
@ -492,138 +493,123 @@ 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.
|
||||
(Contributed by Mark Shannon in :gh:`108362`.)
|
||||
|
||||
|
||||
Other Language Changes
|
||||
======================
|
||||
|
||||
* Classes have a new :attr:`~class.__static_attributes__` attribute, populated by the compiler,
|
||||
with a tuple of names of attributes of this class which are assigned
|
||||
through ``self.X`` from any function in its body. (Contributed by Irit Katriel
|
||||
in :gh:`115775`.)
|
||||
* The compiler now strips common common leading whitespace
|
||||
from every line in a docstring.
|
||||
This reduces the size of the :term:`bytecode cache <bytecode>`
|
||||
(such as ``.pyc`` files), with reductions in file size of around 5%,
|
||||
for example in :mod:`!sqlalchemy.orm.session` from SQLAlchemy 2.0.
|
||||
This change affects tools that use docstrings, such as :mod:`doctest`.
|
||||
|
||||
* The :func:`exec` and :func:`eval` built-ins now accept their ``globals``
|
||||
and ``locals`` namespace arguments as keywords.
|
||||
.. doctest::
|
||||
|
||||
>>> def spam():
|
||||
... """
|
||||
... This is a docstring with
|
||||
... leading whitespace.
|
||||
...
|
||||
... It even has multiple paragraphs!
|
||||
... """
|
||||
...
|
||||
>>> spam.__doc__
|
||||
'\nThis is a docstring with\n leading whitespace.\n\nIt even has multiple paragraphs!\n'
|
||||
|
||||
(Contributed by Inada Naoki in :gh:`81283`.)
|
||||
|
||||
* :ref:`Annotation scopes <annotation-scopes>` within class scopes
|
||||
can now contain lambdas and comprehensions.
|
||||
Comprehensions that are located within class scopes
|
||||
are not inlined into their parent scope.
|
||||
|
||||
.. code-block:: python
|
||||
|
||||
class C[T]:
|
||||
type Alias = lambda: T
|
||||
|
||||
(Contributed by Jelle Zijlstra in :gh:`109118` and :gh:`118160`.)
|
||||
|
||||
* :ref:`Future statements <future>` are no longer triggered by
|
||||
relative imports of the :mod:`__future__` module,
|
||||
meaning that statements of the form ``from .__future__ import ...``
|
||||
are now simply standard relative imports, with no special features activated.
|
||||
(Contributed by Jeremiah Gabriel Pascual in :gh:`118216`.)
|
||||
|
||||
* :keyword:`global` declarations are now permitted in :keyword:`except` blocks
|
||||
when that global is used in the :keyword:`else` block.
|
||||
Previously this raised an erroneous :exc:`SyntaxError`.
|
||||
(Contributed by Irit Katriel in :gh:`111123`.)
|
||||
|
||||
* Add :envvar:`PYTHON_FROZEN_MODULES`, a new environment variable that
|
||||
determines whether frozen modules are ignored by the import machinery,
|
||||
equivalent to the :option:`-X frozen_modules <-X>` command-line option.
|
||||
(Contributed by Yilei Yang in :gh:`111374`.)
|
||||
|
||||
* Add :ref:`support for the perf profiler <perf_profiling>` working
|
||||
without `frame pointers <https://en.wikipedia.org/wiki/Call_stack>`_ through
|
||||
the new environment variable :envvar:`PYTHON_PERF_JIT_SUPPORT`
|
||||
and command-line option :option:`-X perf_jit <-X>`.
|
||||
(Contributed by Pablo Galindo in :gh:`118518`.)
|
||||
|
||||
* The location of a :file:`.python_history` file can be changed via the
|
||||
new :envvar:`PYTHON_HISTORY` environment variable.
|
||||
(Contributed by Levi Sabah, Zackery Spytz and Hugo van Kemenade
|
||||
in :gh:`73965`.)
|
||||
|
||||
* Classes have a new :attr:`~class.__static_attributes__` attribute.
|
||||
This is populated by the compiler with a tuple of the class's attribute names
|
||||
which are assigned through ``self.<name>`` from any function in its body.
|
||||
(Contributed by Irit Katriel in :gh:`115775`.)
|
||||
|
||||
* The compiler now creates a :attr:`!__firstlineno__` attribute on classes
|
||||
with the line number of the first line of the class definition.
|
||||
(Contributed by Serhiy Storchaka in :gh:`118465`.)
|
||||
|
||||
* The :func:`exec` and :func:`eval` builtins now accept
|
||||
the *globals* and *locals* arguments as keywords.
|
||||
(Contributed by Raphael Gaschignard in :gh:`105879`)
|
||||
|
||||
* The :func:`compile` builtin now accepts a new flag,
|
||||
``ast.PyCF_OPTIMIZED_AST``, which is similar to ``ast.PyCF_ONLY_AST``
|
||||
except that the returned AST is optimized according to
|
||||
the value of the *optimize* argument.
|
||||
(Contributed by Irit Katriel in :gh:`108113`).
|
||||
|
||||
* Add :exc:`PythonFinalizationError`, a new exception derived from
|
||||
:exc:`RuntimeError` and used to signal when operations are blocked
|
||||
during :term:`finalization <interpreter shutdown>`.
|
||||
The following callables now raise :exc:`!PythonFinalizationError`,
|
||||
instead of :exc:`RuntimeError`:
|
||||
|
||||
* :func:`_thread.start_new_thread`
|
||||
* :func:`os.fork`
|
||||
* :func:`os.forkpty`
|
||||
* :class:`subprocess.Popen`
|
||||
|
||||
(Contributed by Victor Stinner in :gh:`114570`.)
|
||||
|
||||
* Allow the *count* argument of :meth:`str.replace` to be a keyword.
|
||||
(Contributed by Hugo van Kemenade in :gh:`106487`.)
|
||||
|
||||
* Compiler now strip indents from docstrings.
|
||||
This will reduce the size of :term:`bytecode cache <bytecode>` (e.g. ``.pyc`` file).
|
||||
For example, cache file size for ``sqlalchemy.orm.session`` in SQLAlchemy 2.0
|
||||
is reduced by about 5%.
|
||||
This change will affect tools using docstrings, like :mod:`doctest`.
|
||||
(Contributed by Inada Naoki in :gh:`81283`.)
|
||||
|
||||
* The :func:`compile` built-in can now accept a new flag,
|
||||
``ast.PyCF_OPTIMIZED_AST``, which is similar to ``ast.PyCF_ONLY_AST``
|
||||
except that the returned ``AST`` is optimized according to the value
|
||||
of the ``optimize`` argument.
|
||||
(Contributed by Irit Katriel in :gh:`108113`).
|
||||
|
||||
* :mod:`multiprocessing`, :mod:`concurrent.futures`, :mod:`compileall`:
|
||||
Replace :func:`os.cpu_count` with :func:`os.process_cpu_count` to select the
|
||||
default number of worker threads and processes. Get the CPU affinity
|
||||
if supported.
|
||||
(Contributed by Victor Stinner in :gh:`109649`.)
|
||||
|
||||
* :func:`os.path.realpath` now resolves MS-DOS style file names even if
|
||||
the file is not accessible.
|
||||
(Contributed by Moonsik Park in :gh:`82367`.)
|
||||
|
||||
* Fixed a bug where a :keyword:`global` declaration in an :keyword:`except` block
|
||||
is rejected when the global is used in the :keyword:`else` block.
|
||||
(Contributed by Irit Katriel in :gh:`111123`.)
|
||||
|
||||
* Many functions now emit a warning if a boolean value is passed as
|
||||
a file descriptor argument.
|
||||
This can help catch some errors earlier.
|
||||
(Contributed by Serhiy Storchaka in :gh:`82626`.)
|
||||
|
||||
* Added a new environment variable :envvar:`PYTHON_FROZEN_MODULES`. It
|
||||
determines whether or not frozen modules are ignored by the import machinery,
|
||||
equivalent of the :option:`-X frozen_modules <-X>` command-line option.
|
||||
(Contributed by Yilei Yang in :gh:`111374`.)
|
||||
|
||||
* Add :ref:`support for the perf profiler <perf_profiling>` working without
|
||||
frame pointers through the new environment variable
|
||||
:envvar:`PYTHON_PERF_JIT_SUPPORT` and command-line option :option:`-X perf_jit
|
||||
<-X>` (Contributed by Pablo Galindo in :gh:`118518`.)
|
||||
|
||||
* The new :envvar:`PYTHON_HISTORY` environment variable can be used to change
|
||||
the location of a ``.python_history`` file.
|
||||
(Contributed by Levi Sabah, Zackery Spytz and Hugo van Kemenade in
|
||||
:gh:`73965`.)
|
||||
|
||||
* Add :exc:`PythonFinalizationError` exception. This exception derived from
|
||||
:exc:`RuntimeError` is raised when an operation is blocked during
|
||||
the :term:`Python finalization <interpreter shutdown>`.
|
||||
|
||||
The following functions now raise PythonFinalizationError, instead of
|
||||
:exc:`RuntimeError`:
|
||||
|
||||
* :func:`_thread.start_new_thread`.
|
||||
* :class:`subprocess.Popen`.
|
||||
* :func:`os.fork`.
|
||||
* :func:`os.forkpty`.
|
||||
|
||||
(Contributed by Victor Stinner in :gh:`114570`.)
|
||||
|
||||
* Added :attr:`!name` and :attr:`!mode` attributes for compressed
|
||||
and archived file-like objects in modules :mod:`bz2`, :mod:`lzma`,
|
||||
:mod:`tarfile` and :mod:`zipfile`.
|
||||
* Added :attr:`!name` and :attr:`!mode` attributes
|
||||
for compressed and archived file-like objects in
|
||||
the :mod:`bz2`, :mod:`lzma`, :mod:`tarfile`, and :mod:`zipfile` modules.
|
||||
(Contributed by Serhiy Storchaka in :gh:`115961`.)
|
||||
|
||||
* Allow controlling Expat >=2.6.0 reparse deferral (:cve:`2023-52425`)
|
||||
by adding five new methods:
|
||||
|
||||
* :meth:`xml.etree.ElementTree.XMLParser.flush`
|
||||
* :meth:`xml.etree.ElementTree.XMLPullParser.flush`
|
||||
* :meth:`xml.parsers.expat.xmlparser.GetReparseDeferralEnabled`
|
||||
* :meth:`xml.parsers.expat.xmlparser.SetReparseDeferralEnabled`
|
||||
* :meth:`!xml.sax.expatreader.ExpatParser.flush`
|
||||
|
||||
(Contributed by Sebastian Pipping in :gh:`115623`.)
|
||||
|
||||
* The :func:`ssl.create_default_context` API now includes
|
||||
:data:`ssl.VERIFY_X509_PARTIAL_CHAIN` and :data:`ssl.VERIFY_X509_STRICT`
|
||||
in its default flags.
|
||||
|
||||
.. note::
|
||||
|
||||
:data:`ssl.VERIFY_X509_STRICT` may reject pre-:rfc:`5280` or malformed
|
||||
certificates that the underlying OpenSSL implementation otherwise would
|
||||
accept. While disabling this is not recommended, you can do so using::
|
||||
|
||||
ctx = ssl.create_default_context()
|
||||
ctx.verify_flags &= ~ssl.VERIFY_X509_STRICT
|
||||
|
||||
(Contributed by William Woodruff in :gh:`112389`.)
|
||||
|
||||
* The :class:`configparser.ConfigParser` now accepts unnamed sections before named
|
||||
ones if configured to do so.
|
||||
(Contributed by Pedro Sousa Lacerda in :gh:`66449`.)
|
||||
|
||||
* :ref:`annotation scope <annotation-scopes>` within class scopes can now
|
||||
contain lambdas and comprehensions. Comprehensions that are located within
|
||||
class scopes are not inlined into their parent scope. (Contributed by
|
||||
Jelle Zijlstra in :gh:`109118` and :gh:`118160`.)
|
||||
|
||||
* Classes have a new :attr:`!__firstlineno__` attribute,
|
||||
populated by the compiler, with the line number of the first line
|
||||
of the class definition.
|
||||
(Contributed by Serhiy Storchaka in :gh:`118465`.)
|
||||
|
||||
* ``from __future__ import ...`` statements are now just normal
|
||||
relative imports if dots are present before the module name.
|
||||
(Contributed by Jeremiah Gabriel Pascual in :gh:`118216`.)
|
||||
|
||||
|
||||
New Modules
|
||||
===========
|
||||
|
||||
* :mod:`dbm.sqlite3`: SQLite backend for :mod:`dbm`.
|
||||
* :mod:`dbm.sqlite3`: An SQLite backend for :mod:`dbm`.
|
||||
(Contributed by Raymond Hettinger and Erlend E. Aasland in :gh:`100414`.)
|
||||
|
||||
|
||||
|
|
@ -748,6 +734,23 @@ base64
|
|||
See the `Z85 specification <https://rfc.zeromq.org/spec/32/>`_ for more information.
|
||||
(Contributed by Matan Perelman in :gh:`75299`.)
|
||||
|
||||
|
||||
compileall
|
||||
----------
|
||||
|
||||
* Select the default number of worker threads and processes using
|
||||
:func:`os.process_cpu_count` instead of :func:`os.cpu_count`.
|
||||
(Contributed by Victor Stinner in :gh:`109649`.)
|
||||
|
||||
|
||||
concurrent.futures
|
||||
------------------
|
||||
|
||||
* Select the default number of worker threads and processes using
|
||||
:func:`os.process_cpu_count` instead of :func:`os.cpu_count`.
|
||||
(Contributed by Victor Stinner in :gh:`109649`.)
|
||||
|
||||
|
||||
copy
|
||||
----
|
||||
|
||||
|
|
@ -953,6 +956,15 @@ mmap
|
|||
is inaccessible due to file system errors or access violations.
|
||||
(Contributed by Jannis Weigend in :gh:`118209`.)
|
||||
|
||||
|
||||
multiprocessing
|
||||
---------------
|
||||
|
||||
* Select the default number of worker threads and processes using
|
||||
:func:`os.process_cpu_count` instead of :func:`os.cpu_count`.
|
||||
(Contributed by Victor Stinner in :gh:`109649`.)
|
||||
|
||||
|
||||
opcode
|
||||
------
|
||||
|
||||
|
|
@ -1017,10 +1029,15 @@ os.path
|
|||
* Add :func:`os.path.isreserved` to check if a path is reserved on the current
|
||||
system. This function is only available on Windows.
|
||||
(Contributed by Barney Gale in :gh:`88569`.)
|
||||
|
||||
* On Windows, :func:`os.path.isabs` no longer considers paths starting with
|
||||
exactly one (back)slash to be absolute.
|
||||
(Contributed by Barney Gale and Jon Foster in :gh:`44626`.)
|
||||
|
||||
* :func:`os.path.realpath` now resolves MS-DOS style file names even if
|
||||
the file is not accessible.
|
||||
(Contributed by Moonsik Park in :gh:`82367`.)
|
||||
|
||||
* Add support of *dir_fd* and *follow_symlinks* keyword arguments in
|
||||
:func:`shutil.chown`.
|
||||
(Contributed by Berker Peksag and Tahia K in :gh:`62308`)
|
||||
|
|
@ -1120,6 +1137,26 @@ sqlite3
|
|||
for filtering database objects to dump.
|
||||
(Contributed by Mariusz Felisiak in :gh:`91602`.)
|
||||
|
||||
|
||||
ssl
|
||||
---
|
||||
|
||||
* The :func:`ssl.create_default_context` API now includes
|
||||
:data:`ssl.VERIFY_X509_PARTIAL_CHAIN` and :data:`ssl.VERIFY_X509_STRICT`
|
||||
in its default flags.
|
||||
|
||||
.. note::
|
||||
|
||||
:data:`ssl.VERIFY_X509_STRICT` may reject pre-:rfc:`5280` or malformed
|
||||
certificates that the underlying OpenSSL implementation otherwise would
|
||||
accept. While disabling this is not recommended, you can do so using::
|
||||
|
||||
ctx = ssl.create_default_context()
|
||||
ctx.verify_flags &= ~ssl.VERIFY_X509_STRICT
|
||||
|
||||
(Contributed by William Woodruff in :gh:`112389`.)
|
||||
|
||||
|
||||
statistics
|
||||
----------
|
||||
|
||||
|
|
@ -1285,13 +1322,26 @@ warnings
|
|||
warning may also be emitted when a decorated function or class is used at runtime.
|
||||
See :pep:`702`. (Contributed by Jelle Zijlstra in :gh:`104003`.)
|
||||
|
||||
xml.etree.ElementTree
|
||||
---------------------
|
||||
|
||||
xml
|
||||
---
|
||||
|
||||
* Allow controlling Expat >=2.6.0 reparse deferral (:cve:`2023-52425`)
|
||||
by adding five new methods:
|
||||
|
||||
* :meth:`xml.etree.ElementTree.XMLParser.flush`
|
||||
* :meth:`xml.etree.ElementTree.XMLPullParser.flush`
|
||||
* :meth:`xml.parsers.expat.xmlparser.GetReparseDeferralEnabled`
|
||||
* :meth:`xml.parsers.expat.xmlparser.SetReparseDeferralEnabled`
|
||||
* :meth:`!xml.sax.expatreader.ExpatParser.flush`
|
||||
|
||||
(Contributed by Sebastian Pipping in :gh:`115623`.)
|
||||
|
||||
* Add the :meth:`!close` method for the iterator returned by
|
||||
:func:`~xml.etree.ElementTree.iterparse` for explicit cleaning up.
|
||||
(Contributed by Serhiy Storchaka in :gh:`69893`.)
|
||||
|
||||
|
||||
zipimport
|
||||
---------
|
||||
|
||||
|
|
@ -1447,6 +1497,10 @@ PEP 594: dead batteries (and other module removals)
|
|||
configparser
|
||||
------------
|
||||
|
||||
* The :class:`configparser.ConfigParser` now accepts unnamed sections
|
||||
before named ones if configured to do so.
|
||||
(Contributed by Pedro Sousa Lacerda in :gh:`66449`.)
|
||||
|
||||
* Remove the undocumented :class:`!configparser.LegacyInterpolation` class,
|
||||
deprecated in the docstring since Python 3.2,
|
||||
and with a deprecation warning since Python 3.11.
|
||||
|
|
|
|||
Loading…
Reference in New Issue