puzzles/typing_typevar_constrained.py


1
2
3
4
5
6
7
8
9

from typing import TypeVar, Any, Union

V = TypeVar("V", str, bytes)

def check_v(x: Union[V, list[V]]) -> V:
    raise NotImplementedError()

def foo(a: list[Any]) -> None:
    check_v(a)