gh-105373: Remove PyArg_Parse() deprecation

[vstinner]

There is no plan to deprecate PyArg_Parse().

The deprecation was added as a comment in the C API documentation in 2007 by commit 85eb8c1.

• Issue: Keep deprecated functions in Python 3.13: remove this deprecation #105373

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📚 Documentation preview 📚: https://cpython-previews--105394.org.readthedocs.build/

[vstinner]

@birkenfeld: Hi, do you recall why you considered to deprecated PyArg_Parse() when you documented the bytes() type in 2007?

cc @serhiy-storchaka@pitrou

[methane]

It makes sense because METH_OLDARGS had been deprecated, and removed already.
Having two similar but slightly different unnecessary function confuse users (and other Python implementations.)

[serhiy-storchaka]

PyArg_Parse() is used with METH_O and can be used for parsing separate arguments in other functions (for example if argument can be parsed as "i" or "s"), because there is no other public API for some format units or it is less convenient. You can find many examples in the CPython code.

I believe that it is a useful function and should remain.

[vstinner]

Argument Clinic generates PyArg_Parse() calls for some function signatures.

There are around 69 calls to PyArg_Parse() in the CPython code base, included 15 genereated by Argument Clinic.

If we really want to get ride of it, we should be good citizen and start by cleaning our own code base.

But here I agree with @serhiy-storchaka, this function is fine and should be kept.

If there are use cases where others functions are more appropriated, maybe the doc should be enhanced?
https://docs.python.org/dev/c-api/arg.html#c.PyArg_Parse

@methane: What do you think?

[methane]

I had read only the doc. If there are enough use case for PyArg_Parse, the doc should be updated and deprecation comment should be removed.

[vstinner]

@methane:

I had read only the doc. If there are enough use case for PyArg_Parse, the doc should be updated and deprecation comment should be removed.

I rewrote PyArg_Parse() documentation. Would you mind to review the updated PR?

[birkenfeld]

Just to leave my requested feedback, I don't remember anything about this specific function :)