Python type hinting unions

Question

I have a function with two arguments:

def same_type_params(param1: Union[str, int], param2: Union[str, int]):
    pass

How do I constrain that the types of param1 and param2 are equal? ie either both str or both int

Answer 1

Use a type variable :

from typing import TypeVar
T = TypeVar('T', str, int)
def same_type_params(param1: T, param2: T) -> None:
    pass