python统计一个文本中重复行数的方法

in recent Python 2.7,we have new OrderedDict type,which remembers the order in which the items were added.
>>> d = {"third": 3,"first": 1,"fourth": 4,"second": 2}
>>> for k,v in d.items():
...     print "%s: %s" % (k,v)
...
second: 2
fourth: 4
third: 3
first: 1
>>> d
{'second': 2,'fourth': 4,'third': 3,'first': 1}To make a new ordered dictionary from the original,sorting by the values:
>>> from collections import OrderedDict
>>> d_sorted_by_value = OrderedDict(sorted(d.items(),key=lambda x: x[1]))The OrderedDict behaves like a normal dict:
>>> for k,v in d_sorted_by_value.items():
...     print "%s: %s" % (k,v)
...
first: 1
second: 2
third: 3
fourth: 4
>>> d_sorted_by_value
OrderedDict([('first': 1),('second': 2),('third': 3),('fourth': 4)])

#coding=utf-8
import operator
f = open("f.txt")
count_dict = {}
for line in f.readlines():
    line = line.strip()
    count = count_dict.setdefault(line,0)
    count += 1
    count_dict[line] = count
sorted_count_dict = sorted(count_dict.iteritems(),key=operator.itemgetter(1),reverse=True)
for item in sorted_count_dict:
    print "%s,%d" % (item[0],item[1])

>>> help(sorted)
Help on built-in function sorted in module __builtin__:
sorted(...)
    sorted(iterable,cmp=None,key=None,reverse=False) --> new sorted list