fix: make PyType::name consistent with __name__ and add PyType::module

[wyfo]

fixes #4055

[adamreichold]

I am not particularly keen on the additional complexity and would be prefer to limit to fixing inconsistencies between builds with and without abi3.

[davidhewitt]

As well as efficiency, it looks like PEP 737 makes it clear that exposing tp_name is a bad idea. Even though we just changed the way these worked in 0.21, I think it's probably correct to change PyType::name to just match __name__ in 0.22. Sigh.

However I agree with the complexity concern here.

Given that PEP 737 adds a new PyType_GetFullyQualifiedName function to Python 3.13, I suggest what we should do is not have PyType::full_name at all, and instead add PyType::fully_qualified_name which will be __module__.__qualname__ as per PEP 737. We can even use the API function on new Python versions.

That way we have a set of functions which match Python well, and should be relatively simple to implement:

• PyType::name for __name__
• PyType::qualname for __qualname__
• PyType::module for __module__
• PyType::fully_qualified_name for __module__.__qualname (as per PEP 737 rules of when to skip __module__).

What do you both think of this?

[wyfo]

I prefer to be aligned with Python dunder attributes, I find this more intuitive.

[davidhewitt]

@adamreichold as you already raised a complexity concern, what do you think of what I suggest above?

[davidhewitt]

Ping @adamreichold (and other maintainers), what do you think of this? I still believe we errored in the design for 0.21 and this correction is worthwhile despite the churn.

[adamreichold]

Ping @adamreichold (and other maintainers), what do you think of this? I still believe we errored in the design for 0.21 and this correction is worthwhile despite the churn.

Yes, I agree that PEP compliance is preferable and outweighs the perceived performance benefits of borrowing tp_name. I just did not find the spare time to look into the implementation yet. Sorry for that.

[davidhewitt]

No problem, I am happy to also try to implement (or maybe @wyfo is willing to rework this PR). Mostly just wanted to make sure the design blocker was removed!

[davidhewitt]

Superseded by #4196. I will close this one.