gh-108901: Deprecate inspect.getargvalues and inspect.formatargvalues, provide modern alternative

[sobolevn]

Now getargvalues is deprecated (together with formatargvalues). People should use Signature object instead.

inspect313 backports new Signature.from_frame to 3.8-3.12: https://github.com/wemake-services/inspect313/blob/a310c03c440156062504b14a6325fbbe84687052/inspect313/__init__.py#L25-L48 and https://github.com/wemake-services/inspect313/blob/master/README.md#replace-inspectgetargvalues-with-inspectsignaturefrom_frame

• Issue: Add modern alternatives to inspect module, deprecate old incorrect APIs #108901

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[vkhodygo]

Any progress?

[sobolevn]

@hugovk I've implemented your suggestion about porting to Python 3.13, please take a look.
@AlexWaygood We discussed this deprecation in #112279

[vstinner]

Please start with a separated PR which adds Signature.from_frame(). Once it will be merge, you can simplify this PR to only deprecate methods.

[vstinner]

It seems like you can move if frame.f_locals: out of this loop and the one below.

[hugovk]

(Copying and pasting my reply from elsewhere :)

PEP 387 says two releases of deprecation is the minimum but also:

• If the deprecated feature is replaced by a new one, it should generally be removed only after the last Python version without the new feature reaches end of support.

Does that apply here? If so, and if the replacement is added in 3.13, then the removals should be when 3.13 is EOL in October 2029, meaning removal in 3.18, not 3.15.

[vstinner]

Using a global sounds like a bad idea. You can use a "nonlocal" instead.

Sometimes, I use a mutable type instead, which is more or less the same:

ns = {}
def func():
    ns['name'] = value