tips.py

#!/usr/bin/env python

#------------------------------------------
a = 1
b = 2
c = 3
a,b,c = b,c,a
print a,b,c

a = [1]
b = [2]
c = [3]
a,b,c = b,c,a
print a,b,c

class Node(object):
    def __init__(self,x):
        self.val = x


#等号左边的值的赋值是从左往右有先后关系的，右边在赋值时值已经固定了???
a = Node(1)
b = Node(2)
c = Node(3)
a,b,c = b,c,a
print a.val,b.val,c.val

a = Node(1)
b = Node(2)
c = Node(3)
a,a,c = b,c,a
print a.val,b.val,c.val

#------------------------------------------