借助 Type Hint 进行运行时类型检查的 Python 装饰器

type_check.py

# https://aboutsimon.com/blog/2018/04/04/Python3-Type-Checking-And-Data-Validation-With-Type-Hints.html

from functools import wraps
from inspect import getfullargspec
from typing import get_type_hints


def validate_input(hints, **kwargs):
    # iterate all type hints
    for attr_name, attr_type in hints.items():
        if attr_name == 'return':
            continue

        if not isinstance(kwargs[attr_name], attr_type):
            raise TypeError(f'Argument {attr_name} is not of type {attr_type}')


def type_check(decorator):
    @wraps(decorator)
    def wrapped_decorator(*args, **kwargs):
        # translate *args into **kwargs
        func_args = getfullargspec(decorator)[0]
        kwargs.update(dict(zip(func_args, args)))

        hints = get_type_hints(decorator)
        validate_input(hints, **kwargs)

        ret = decorator(**kwargs)

        if not isinstance(ret, hints['return']):
            raise TypeError(f'Return value is not of type {hints["return"]}')

        return ret

    return wrapped_decorator