A question about type narrowing

[uf-fipper]

pylance version: 2023.12.1

Look at the following code:

from typing import TypeAlias, TypeVar

IntOrStr: TypeAlias = int | str
IntOrStrT = TypeVar("IntOrStrT", bound=IntOrStr)

def func(a: IntOrStrT) -> IntOrStrT:
    if isinstance(a, int):
        ...
        a.as_integer_ratio  # Cannot access member "as_integer_ratio" for type "str*"
    else:
        ...
    return a

There is an error at line a.as_integer_ratio: Cannot access member "as_integer_ratio" for type "str*". Is this normal? There is no error in version 2023.11.10.

[erictraut]

This has been fixed in a newer version of pyright (the type checker upon which pylance is built). If you switch to the prerelease version of pylance, the error should go away.

[heejaechang]

fixed in 2023.12.100 preview.