Check for int | float

[srittau]

As float is a subtype of int (for type checking purposes), int is redundant. There might be other constellations that are worth checking.

[AlexWaygood]

For numeric types, the following are redundant (according to PEP 484):

• float | int (int is an implicit subtype of float)
• complex | float (float is an implicit subtype of complex)
• complex | int (int is an implicit subtype of complex)

[Zeckie]

But at runtime, they aren't subtypes (eg. using type, isinstance or mro), and they have some differences that would not be allowed if they were subtypes.

eg. float has is_integer() but int does not

python/mypy#11511 (comment)

[hauntsaninja]

Yes, that is true. But all static type checkers treat them this way and PEP 484 isn't going to change on this point. If anything, this makes even more of a case for linting here, since it alerts users to a mismatch between their expectations of how int float subtyping works and the reality of PEP 484.

[AlexWaygood]

This issue was fixed by #222, so I'm closing it now.