gh-98852: Add extra type check to avoid a bug with parameterizing gen…

[Eclips4]

• Issue: Bug or new behavior of generics parameterization? #98852

[sobolevn]

You would need to:

1. Add NEWS, consider using blurb CLI or online services. See news CI job logs
2. Add tests: at least the example from the original bug report. But, I like when there are lots of tests :)

[Eclips4]

I find only one way how to write test for it:

classBaseCallableTests:
...
deftest_determine_new_args(self):
Callable=self.CallableT=TypeVar("T")
P=TypeVar("P")
classC(Generic[T]): ...
S=Callable[[C], P]
U=S[T]
ifself.Callableiscollections.abc.Callable:
self.assertEqual(U, Callable[[C[T]], T])
else:
self.assertEqual(U, Callable[[C], T])
...

What u think about this?
And i have one question,

fromtypingimportTypeVar, Genericfromcollections.abcimportCallablefromtypingimportCallableasTypingCallableT=TypeVar("T")
P=TypeVar("P")
Z=TypeVar("Z")
classC(Generic[Z]): ...
S=Callable[[C], P]
U=S[T]
U>collections.abc.Callable[[__main__.C[~Z]], ~T]
S_T=TypingCallable[[C], P]
U_T=S_T[T]
U_T>typing.Callable[[__main__.C], ~T]

Is it okay?

[sobolevn]

It does not look right that two callables have different results.

[Eclips4]

I think, problem was solved in this PR: #98952
But, question about collections.abc.Callable and typing.Callable still relevant.

[JelleZijlstra]

Closing in favor of #98952. I can't reproduce the Callable difference on current main:

Python 3.12.0a1+ (heads/pep688v2-dirty:007fdc1153, Nov 7 2022, 06:50:30) [Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from typing import TypeVar, Generic
>>> from collections.abc import Callable
>>> from typing import Callable as TypingCallable
>>> >>> >>> T = TypeVar("T")
>>> P = TypeVar("P")
>>> Z = TypeVar("Z")
>>> >>> class C(Generic[Z]): ...
... >>> S = Callable[[C], P]
>>> U = S[T]
>>> U
collections.abc.Callable[[__main__.C], ~T]
>>> S_T = TypingCallable[[C], P]
>>> U_T = S_T[T]
>>> U_T
typing.Callable[[__main__.C], ~T]