[C API] Add PyLong_AsInt() public function

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Feature or enhancement

Has this already been discussed elsewhere?

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Links to previous discussion of this feature:

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Proposal:

The _PyLong_AsInt() function was added in 2013 by commit 74f49ab. It was added a private function (_Py) prefix and it's not part of the limited C API.

This function is widely used in the Python code base which means that it's useful. Casting PyLong_AsLong() to int and then checking for overflow is error prone, it requires to raise the right exception.

Using a private function is a bad practive: I removed many private functions from Python 3.13 C API, see issue #106320.

I propose to add PyLong_AsInt() to the limited C API, add documentation and tests.

Linked PRs

• gh-108444: Add PyLong_AsInt() public function #108445
• gh-108444: Argument Clinic uses PyLong_AsInt() #108458
• gh-108444: Replace _PyLong_AsInt() with PyLong_AsInt() #108459
• gh-108444: Remove _PyLong_AsInt() function #108461