backport contextlib from python 3.12

[graingert]

python/cpython@6cb145d

A TypeError is now raised instead of an AttributeError in contextlib.ExitStack.enter_context() and contextlib.AsyncExitStack.enter_async_context() for objects which do not support the context manager or asynchronous context manager protocols correspondingly. (Contributed by Serhiy Storchaka in bpo-44471.)

however this is only to match the change in behaviour of the async with and with statements in 3.11:

A TypeError is now raised instead of an AttributeError in with and async with statements for objects which do not support the context manager or asynchronous context manager protocols correspondingly. (Contributed by Serhiy Storchaka in bpo-12022.)

so would need conditional checking.

perhaps:

if sys.version_info >= (3, 11):
    from contextlib import ExitStack, AsyncExitStack
else:
    class ExitStack(...):
        ...

    class AsyncExitStack(...):
        ...

would be best?

[graingert]

this will need to wait for a 3.11 to be available on github actions at least

[graingert]

also support for contextlib.chdir will need the changes in typeshed first: python/typeshed#6191

[hrnciar]

Hello, is there any progress on this? I think Python 3.11 is now available on GitHub Actions.

[opoplawski]

Fedora is now updating to 3.11 so it would be great if this could be fixed. Thanks.

[mr-c]

python/typeshed#6191 is fixed, and Python 3.11 is available from GitHub Actions

[ncoghlan]

For the TypeError/AttributeError change, I'll likely just add a small snippet of code to set an _IncompatibilityError module global at import time. Conditionally importing the stdlib versions doesn't work since one of goals of contextlib2 is that its behaviour should mostly be based on the package version rather than the Python version (while in this specific case raising the same error as the underlying statements would raise feels like the right approach, pulling in all future changes in any 3.x release feels like overkill).

Since it has taken me so long to do anything about it, I've also updated the issue title to cover syncing with 3.12 rather than with 3.11 (there haven't actually been any changes to the stdlib module since 3.12.1, so this is effectively syncing with 3.13, but I think describing it as syncing with 3.12 will be clearer)

[ncoghlan]

Noting the other changes since 3.10:

• 3.11: new chdir CM
• 3.12: improved handling of BaseExceptionGroup in suppress
• potentially some other smaller bugfixes (3.12 changelog doesn't make the timing clear, but the diff on the update will)