python-闭包应用二传递函数

#! /usr/bin/env python
# -*- coding:utf-8 -*-

def my_sum(*arg):
    return sum(arg)

def my_average(*arg):
    return sum(arg)/len(arg)

#print(my_sum(1,2,3,4,5))
#print(my_sum(1,2,3,4,5,'6'))  #报错。不支持的类型
#print(my_average(1,2,3,4,5))
#print(my_average()) # 报错长度为0除以0所以报错




#为了提高代码的健壮性需要加入判断
'''
def my_sum(*arg):
    if len(arg) == 0:
        return 0
    for val in arg:
        if not isinstance(val,int):
            return 0
    return sum(arg)

def my_average(*arg):
    if len(arg) == 0:
        return 0
    for val in arg:
        if not isinstance(val,int):
            return 0
    return sum(arg)/len(arg)
'''



# 为了提高上述判断代码的复用性，可以使用闭包来实现

def my_sum(*arg):
    return sum(arg)

def my_average(*arg):
    return sum(arg)/len(arg)




def dec(func):
    def in_dec(*arg):
        if len(arg) == 0:
            return 0
        for val in arg:
            if not isinstance(val,int):
                return 0
        return func(*arg) 

    return in_dec

my_sum = dec(my_sum)
#sum = my_sum(1,2,3)
my_average = dec(my_average)
print(my_sum(1,2,3,4,5))
print(my_sum(1,2,3,4,5,'6'))  
print(my_average(1,2,3,4,5))
print(my_average())