列表中重复元素的个数

from collections import defaultdict,Counter

-------------1

dd=defaultdict(int)
for item in names:
  dd[item]+=1
for k,v in dd.iteritems():
  pass
-------------2

for item in set(names):
  a=names.count(item)
-------------3

c=Counter(names)
for k,v in dict(c).iteritems():
  pass

1、3差不多，2最慢