The following code fails to type check with error: "str" has no attribute "bit_length" on the match statement, but not on the print statement:

def redefinition(a: str):
    a = int(a)

    print(a.bit_length())

    match a.bit_length():
        case _:
            ...

The same function without the match statement passes type checking, see https://mypy-play.net/?mypy=master&python=3.11&flags=allow-redefinition&gist=ab4ccfc9e1db52c94b98c8b4d790e7d1

The opposite case does pass type checking while it shouldn't:

def redefinition_other_way(a: int):
    a = str(a)

    match a.bit_length():
        case _:
            ...

It seems like match statements do not consider redefinitions properly.

Your Environment

• Mypy version used: ed3a6c1
• Mypy command-line flags: --allow-redefinition
• Python version used: Python 3.10.9