.. bpo: 32381
.. date: 2020-12-04-17-17-44
.. nonce: NY5t2S
.. release date: 2020-12-21
.. section: Core and Builtins

Fix encoding name when running a ``.pyc`` file on Windows:
:c:func:`PyRun_SimpleFileExFlags()` now uses the correct encoding to decode
the filename.

..

.. bpo: 42536
.. date: 2020-12-02-20-23-31
.. nonce: Kx3ZOu
.. section: Core and Builtins

Several built-in and standard library types now ensure that their internal
result tuples are always tracked by the :term:`garbage collector <garbage
collection>`:

- :meth:`collections.OrderedDict.items() <collections.OrderedDict>`

- :meth:`dict.items`

- :func:`enumerate`

- :func:`functools.reduce`

- :func:`itertools.combinations`

- :func:`itertools.combinations_with_replacement`

- :func:`itertools.permutations`

- :func:`itertools.product`

- :func:`itertools.zip_longest`

- :func:`zip`

Previously, they could have become untracked by a prior garbage collection.
Patch by Brandt Bucher.

..

.. bpo: 42630
.. date: 2020-12-15-17-51-27
.. nonce: jf4jBl
.. section: Library

:mod:`tkinter` functions and constructors which need a default root window
raise now :exc:`RuntimeError` with descriptive message instead of obscure
:exc:`AttributeError` or :exc:`NameError` if it is not created yet or cannot
be created automatically.

..

.. bpo: 42644
.. date: 2020-12-15-10-00-04
.. nonce: XgLCNx
.. section: Library

`logging.disable` will now validate the types and value of its parameter. It
also now accepts strings representing the levels (as does `loging.setLevel`)
instead of only the numerical values.

..

.. bpo: 36541
.. date: 2020-12-14-08-23-57
.. nonce: qdEtZv
.. section: Library

Fixed lib2to3.pgen2 to be able to parse PEP-570 positional only argument
syntax.

..

.. bpo: 42375
.. date: 2020-11-19-04-13-53
.. nonce: U8bp4s
.. section: Library

subprocess module update for DragonFlyBSD support.

..

.. bpo: 39825
.. date: 2020-10-20-08-28-26
.. nonce: n6KnG0
.. section: Library

Windows: Change ``sysconfig.get_config_var('EXT_SUFFIX')`` to the expected
full ``platform_tag.extension`` format. Previously it was hard-coded to
``.pyd``, now it is compatible with ``distutils.sysconfig`` and will result
in something like ``.cp38-win_amd64.pyd``. This brings windows into
conformance with the other platforms.

..

.. bpo: 39101
.. date: 2020-10-11-21-43-03
.. nonce: -I49Pm
.. section: Library

Fixed tests using IsolatedAsyncioTestCase from hanging on BaseExceptions.

..

.. bpo: 41907
.. date: 2020-10-02-10-19-49
.. nonce: wiIEsz
.. section: Library

fix `format()` behavior for `IntFlag`

..

.. bpo: 41889
.. date: 2020-10-01-16-17-11
.. nonce: qLkNh8
.. section: Library

Enum: fix regression involving inheriting a multiply-inherited enum

..

.. bpo: 41891
.. date: 2020-09-30-13-35-29
.. nonce: pNAeYI
.. section: Library

Ensure asyncio.wait_for waits for task completion

..

.. bpo: 40219
.. date: 2020-07-13-19-43-11
.. nonce: MUoJEP
.. section: Library

Lowered :class:`tkinter.ttk.LabeledScale` dummy widget to prevent hiding
part of the content label.

..

.. bpo: 40084
.. date: 2020-03-29-21-32-00
.. nonce: MCYwcv
.. section: Library

Fix ``Enum.__dir__``: dir(Enum.member) now includes attributes as well as
methods.

..

.. bpo: 17140
.. date: 2020-12-16-21-06-16
.. nonce: 1leSEg
.. section: Documentation

Add documentation for the :class:`multiprocessing.pool.ThreadPool` class.

..

.. bpo: 42604
.. date: 2020-12-20-02-35-28
.. nonce: gRd89w
.. section: Build

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"). Previosuly only Linux, Mac and VxWorks were using a value
for "EXT_SUFFIX" that included "SOABI".

..

.. bpo: 42598
.. date: 2020-12-13-14-43-10
.. nonce: 7ipr5H
.. section: Build

Fix implicit function declarations in configure which could have resulted in
incorrect configuration checks.  Patch contributed by Joshua Root.

..

.. bpo: 42613
.. date: 2020-12-16-09-10-32
.. nonce: J-jnm5
.. section: Tools/Demos

Fix ``freeze.py`` tool to use the prope config and library directories.
Patch by Victor Stinner.