enumerate 函数用于遍历序列中的元素以及它们的下标

for  i,v in  enumerate(['tic','tac','toe']):    print  i,v    #0 tic#1 tac#2 toefor i,j in enumerate(('a','b','c')):    print i,j    #0 a#1 b#2 cfor i,j in enumerate({'a':1,'b':2}):    print i,j#0 a#1 b

 遍历字典的key和value

knights={'galahad':'the pure','robin':'the brave'}for  k,v  in  knights.iteritems():    print  k,v #galahad the pure#robin the brave