.. bpo: 13487
.. date: 2020-03-04-16-10-59
.. nonce: gqe4Fb
.. release date: 2020-03-10
.. section: Library

Avoid a possible *"RuntimeError: dictionary changed size during iteration"*
from :func:`inspect.getmodule` when it tried to loop through
:attr:`sys.modules`.

..

.. bpo: 17422
.. date: 2020-02-27-17-35-27
.. nonce: eS1hVh
.. section: Documentation

The language reference no longer restricts default class namespaces to dicts
only.