Type hinting produces "TypeError: type object is not subscriptable"

Question

w: dict[int, int] = {1:2, 2:3, 69: 420} produces the error message in the title. Why won't specific type hints work for my dictionaries and lists?

Answer 1

As of python3.8, you need to import their respective classes from the typing module.

from typing import Dict, List, Set

w: Dict[int, int] = {1:2, 2:3, 69:420}

Note the capital D in Dict.