Python实现两个list求交集，并集，差集的方法示例

#!/usr/bin/env python
#coding:utf-8
'''
Created on 2016年6月9日
@author: lei.wang
'''
def diff(listA,listB):
 #求交集的两种方式
 retA = [i for i in listA if i in listB]
 retB = list(set(listA).intersection(set(listB)))
 print "retA is: ",retA
 print "retB is: ",retB
 #求并集
 retC = list(set(listA).union(set(listB)))
 print "retC1 is: ",retC
 #求差集，在B中但不在A中
 retD = list(set(listB).difference(set(listA)))
 print "retD is: ",retD
 retE = [i for i in listB if i not in listA]
 print "retE is: ",retE
def main():
 listA = [1,2,3,4,5]
 listB = [3,4,5,6,7]
 diff(listA,listB)
if __name__ == '__main__':
 main()