python 统计并排序文字出现的个数

#!/usr/bin/env python
#Filename:readfile.py
codelist=[]
f=file('input.txt','r')
lines = f.readlines();
for i in range(len(lines)):
     line=lines[i].strip('\n');
     print line
     codelist+=line
print codelist
###########################################
map={}
for i in codelist:
    if map.has_key(i)==False:
        map.setdefault(i,1)
    else:
        count=map.get(i)+1
        map[i]=count
print map
###########################################
#      sort map                           #
#      sort map                           #
###########################################
map=sorted(map.iteritems(),key=lambda asd:asd[1],reverse=True)
print map
list_map=list(map);


fo=file('output.txt','w')
for i in list_map:
     i_list = list(i)
     fo.write(str(i_list[0]))
     print str(i_list[0])
     fo.write("\t \t \t \t")
     fo.write(str(i_list[1]))
     print "\n"
     print str(i_list[1])
     fo.write("\n")
f.close()
fo.close()