python 允许对函数参数和返回值类型进行标注,但实际上并不起任何作用,只是看起来方便。
def test(x:int,y:int)->int:
''' x and y must be integers,return an integer x+y'''
assert isinstance(x,int),'x must be integer'
assert isinstance(y,int),'y must be integer'
z=x+y
assert isinstance(z,int),'must return an integer'
return z
test(1,2.0)