为函数的参数指定类型

@typeassert(int, int, list)实现 java中 String name, int age 这种形式的参数,
Python 参数必须为指定类型.如不符合则raise 错误信息.

from inspect import signature
def typeassert(*ty_args, **ty_kwargs):
    def decorator(func):
        sig = signature(func)
        btypes = sig.bind_partial(*ty_args, **ty_kwargs).arguments

        def wrapper(*args, **kwargs):
            for name, obj in sig.bind(*args, **kwargs).arguments.items():
                if name in btypes:
                    if not isinstance(obj, btypes[name]):
                        raise TypeError('%s must be%s' % (name,btypes[name]))
            return func(*args, **kwargs)

        return wrapper

    return decorator


@typeassert(int, int, list)
def f(a, b, c):
    print(a, b, c)


f(1, "aa", [1, 2])