Add support for Python 3.12

[hugovk]

What do these changes do?

The Python 3.12 release candidate is out! 🚀

Call to action

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.12 compatibilities during this phase, and where necessary publish Python 3.12 wheels on PyPI to be ready for the final release of 3.12.0.

See also https://dev.to/hugovk/help-test-python-312-beta-1508/

Are there changes in behavior for the user?

No.

Related issue number

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• Add a new news fragment into the CHANGES folder
  • name it <issue_id>.<type> (e.g. 588.bugfix)
  • if you don't have an issue_id change it to the pr id after creating the PR
  • ensure type is one of the following:
    • .feature: Signifying a new feature.
    • .bugfix: Signifying a bug fix.
    • .doc: Signifying a documentation improvement.
    • .removal: Signifying a deprecation or removal of public API.
    • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: Fix issue with non-ascii contents in doctest text files.

[hugovk]

This will fail with a segmentation fault (https://github.com/hugovk/multidict/actions/runs/6028022143), already reported at #862.

And it will be fixed by #864.

To demonstrate, here's a branch (https://github.com/hugovk/multidict/tree/add-3.12b) with both this PR and that PR's commits which passes (https://github.com/hugovk/multidict/actions/runs/6029781394).

[h-vetinari]

Compiling 6.0.4 + #864 with clang >=15 errors due to using NULL (which has type void *) to initialize an integer.

  multidict/_multidict.c:458:37: error: incompatible pointer to integer conversion initializing 'int' with an expression of type 'void *' [-Wint-conversion]
      static _PyArg_Parser _parser = {NULL, _keywords, "getall", 0};
                                      ^~~~
  /Users/runner/miniforge3/conda-bld/multidict_1696714043821/_build_env/lib/clang/15.0.7/include/stddef.h:89:16: note: expanded from macro 'NULL'
  #  define NULL ((void*)0)
                 ^~~~~~~~~~

[guidopetri]

@asvetlov @webknjaz any ETA on this being merged in + released?

[davepeck]

@h-vetinari

Compiling 6.0.4 + #864 with clang >=15 errors due to using NULL (which has type void *) to initialize an integer.

I run into this too on my Mac with clang version 17.0.4 and when using python 3.12.

Since so many packages transitively depend on multidict under the hood (openai and litestar, to name just two examples), I've taken to temporarily invoking pip install with:

CFLAGS="-Wno-error=int-conversion" pip install ...

It ain't pretty; I have no intention of doing this in production; I'll probably regret it even for my local dev projects. But there you have it.

[robd003]

@asvetlov can we get some 👀 on this?

Python 3.12 has been available for over 2 months now

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (780a1e1) 93.65% compared to head (b3c777f) 93.65%.

❗ Current head b3c777f differs from pull request most recent head 92c7881. Consider uploading reports for the commit 92c7881 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #877   +/-   ##
=======================================
  Coverage   93.65%   93.65%           
=======================================
  Files           5        5           
  Lines         504      504           
=======================================
  Hits          472      472           
  Misses         32       32           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.