1  for key in dic:                          #循环一个字典
2      print key,dic.get(key)
3  for k ,v in dic.items():
4      print  k,v

1 # -*-  coding:utf-8 -*-
2 
3 s1 ={"a","b","c","d"}
4 s2 ={"a","b","f"}
5 print s1.difference(s1)   #计算两个集合不同的部分
6 print s1.intersection(s1)  #交集
7 print  s1.issubset(s2)  #判断s1是否是s2的子集
8 print s1.issuperset(s2)  #判断s1是否是s2的父集
9 #