As discovered inprompt-toolkit/python-prompt-toolkit#1696, it appears that the DeprecationWarning introduced in Python 3.10 has expanded its scope, now with 3.11.1 and 3.10.9 emitting during get_event_loop_policy() where it did not before:

 ~ $ py -3.11 -W errorPython 3.11.0 (main, Oct 26 2022, 19:06:18) [Clang 14.0.0 (clang-1400.0.29.202)] on darwinType "help", "copyright", "credits" or "license" for more information.>>> import asyncio>>> asyncio.get_event_loop_policy().get_event_loop()<_UnixSelectorEventLoop running=False closed=False debug=False>>>> ^D ~ $ docker run -it jaraco/multipy-tox py -3.11 -W errorPython 3.11.1 (main, Dec  7 2022, 01:11:34) [GCC 11.3.0] on linuxType "help", "copyright", "credits" or "license" for more information.>>> import asyncio>>> asyncio.get_event_loop_policy().get_event_loop()Traceback (most recent call last):  File "<stdin>", line 1, in <module>  File "/usr/lib/python3.11/asyncio/events.py", line 687, in get_event_loop    warnings.warn('There is no current event loop',DeprecationWarning: There is no current event loop

It's not obvious if it was intentional to expand the scope of the DeprecationWarning, but it does come as a surprise as the calling code had previously attempted to address the deprecation.

I think there are two concerns to be addressed:

• Does this symptom indicate an unintentional but real additional path that was previously unprotected by the DeprecationWarning? And if so, does that imply that the behavior's first true deprecation is in Python 3.12 and thus will delay the removal?
• What is a user expected to do to properly address the deprecation? I read thewhat's new for Python 3.10 and it indicates that the call is deprecated, but it provides little guidance on how a user can adapt to the new behavior. Maybe there should be a note to the effect of "programs relying on a non-running event loop must ensure that there is a running event loop before attempting to get the event loop."

Linked PRs

• gh-100160: Restore and deprecate implicit creation of an event loop #100410
• [3.11] gh-100160: Remove any deprecation warnings in asyncio.get_event_loop() #100412
• [3.11] gh-100160: Tweak the documentation for the default asyncio policy #100969
• [3.10] [3.11] gh-100160: Remove any deprecation warnings in asyncio.g… #100970