Type strict in python 3.5

main.py

import inspect


def use_strict(func):
    signature = inspect.signature(func)

    def validate_args(*args):
        params = signature.parameters.values()
        types = map(lambda p: p.annotation, params)
        zipped = zip(list(*args), types)
        for i, t in enumerate(zipped):
            if t[1] is not None and not isinstance(t[0], t[1]):
                raise TypeError("Unexpected type of parameter")

    def validate_return(result):
        if signature.return_annotation is not None \
                and not isinstance(result, signature.return_annotation):
            raise TypeError("Unexpected type of return value")

    def func_wrapper(*args, **kwargs):
        validate_args(args)
        r = func(*args, **kwargs)
        validate_return(r)
        return r
    return func_wrapper


@use_strict
def my_sum(x: int, y: int) -> int:
    return x + y

# Will run ok
print(my_sum(10, 15))

# Will raise error
# print(my_sum("foo", "bar"))