是否可以直接使用类型提示验证？

Question

With version 3.6 python has type hints:

from typing import List, Union

def foo() -> List[Union[str, int]]:
    return 3

However can we use this syntax outside of intended scope?
ie Can we use this syntax to validate some object?

objects = [['foo', 1], ['bar', 2.2]]
for object in objects:
    if not isinstance(object, List[Union[str, int]]):
        print(f'error, invalid object: {object}')

Answer 1

You can install the typeguard module :

from typeguard import check_type
from typing import Tuple
objects = [('foo', 1), ('bar', 2.2)]
for object in objects:
    try:
        check_type('object', object, Tuple[str, int])
    except TypeError as e:
        print(e)

This outputs:

type of object[1] must be int; got float instead