方法1：(错误)
def func(a,b): a,b = b,a a = 1 b = 2 func(a,b) print(a," ",b)
方法2：（正确）
def func(a,b): return b,a a = 1 b = 2 a,b = func(a,b) print(a," ",b)
Python交换两个变量值的函数
原文：https://www.cnblogs.com/luojianyi/p/9573990.html
