给函数参数增加元信息

def add(x: int, y: int) -> int:
    return x + y
help(add)
print('-' * 50)
print(add.__annotations__)

运行结果:

Help on function add in module __main__:
add(x: int, y: int) -> int
--------------------------------------------------
{'x': <class 'int'>, 'y': <class 'int'>, 'return': <class 'int'>}