Example on how to use Iterable type instead of List to make mypy happy :)

iterable_static_type_checking.py

"""Static type checking using Iterable

show function receives List[Base]. However, if I specify type as List[Base]
mypy will return following error:

error: Argument 1 to "show" has incompatible type "List[Double]"; expected "List[Base]"

To fix it use Iterable[Base] instead

Output:
Base(0)
Base(1)
Base(2)
Base(3)
Base(4)

Double(20)
Double(22)
Double(24)
Double(26)
Double(28)
Double(30)
"""

from typing import Iterable


class Base:
    def __init__(self, x: int) -> None:
        self.x = x

    def __repr__(self) -> str:
        return f"Base({self.x})"


class Double(Base):
    def __init__(self, x: int) -> None:
        super().__init__(x * 2)

    def __repr__(self) -> str:
        return f"Double({self.x})"


def show(items: Iterable[Base]) -> None:
    print("\n".join(str(x) for x in items))


a = [Base(i) for i in range(5)]
b = [Double(i) for i in range(10, 16)]

show(a)
show(b)