Adapt ast types for mypy 0.990

[kasium]

With mypy 0.990 the complex/int/float promotion was changed (see python/mypy#14030).
Therefore checks like isinstance(node, ast.Num) and isinstance(node.n, int) fails with strict mode enabled.

The recommendation by mypy is to change complex to Union[int, float, complex]. Are there any objections to do so in the ast module?

[srittau]

I'm not sure what you would want to change. Stubs don't use isinstance checks.

[kasium]

Ah sorry;

so in my code I use code like isinstance(node, ast.Num) and isinstance(node.n, int) and this fails now with mypy 0.990 (see python/mypy#14030). The recommendation by mypy is to adapt the types of ast.Num.n to be Union[int, float, complex] instead of complex (which implies int and float but not explicitly enough for mypy).

Proposal: change complex types in _ast.pyi to be Union[int, float, complex]

[ilevkivskyi]

FWIW I also think n for both Num and Constant should be Union[int, float, complex]. This is more correct, and doesn't implicitly rely on type promotions.

[kasium]

Okay, let me then give a PR a try

[ilevkivskyi]

Hm, as noticed in the PR, it looks like tpyeshed is using a flake8 lint rule that actually prohibits int | float. This is bad, there is a chance there are some other places with incorrect plain complex annotations.

@srittau I would propose to disable this rule globally.

[ilevkivskyi]

I briefly scrolled through and found only other problematic annotations in typed-ast https://github.com/python/typeshed/blob/main/stubs/typed-ast/typed_ast/ast27.pyi#L241 and https://github.com/python/typeshed/blob/main/stubs/typed-ast/typed_ast/ast3.pyi#L260. @kasium maybe you can add these to your PR?

[kasium]

sure!