for key in dic:                          #循环一个字典

      print key,dic.get(key)

  for k ,v in dic.items():

      print  k,v

 # -*-  coding:utf-8 -*-

 s1 ={"a","b","c","d"}

 s2 ={"a","b","f"}

 print s1.difference(s1)   #计算两个集合不同的部分

 print s1.intersection(s1)  #交集

 print  s1.issubset(s2)  #判断s1是否是s2的子集

 print s1.issuperset(s2)  #判断s1是否是s2的父集

 #