2018/05/14 ：用python 实现交换两个变量的值

#-*- coding:utf-8 -*-
# 交换两个变量的值
a = float(raw_input("Please input number A : "))
b = float(raw_input("Please input number B : "))
print a ,b
c = a
a = b
b = c

print a,b