python获取文件后缀名及批量更新目录下文件后缀名的方法

#coding:utf-8

import os

#获取文件后缀名称
dict = {}   #存放文件后缀名
path = r'E:\test\'

for  dirpath,dirnames,filenames in os.walk(path):
for filename in filenames:
sufix = os.path.splitext(filename)[1][1:]
if dict.has_key(sufix):
dict[sufix]+=1
else:
dict[sufix] = 1

for item in dict.items():
print '%s:%s' %item

#查找遍历指定文件路径下指定后缀名的文件实例
for dirpath,dirnames,filenames in os.walk(path):
for filename in filenames:
if os.path.splitext(filename)[1] == '.txt':
filepath = os.path.join(dirpath,filename)
print 'file:'+filepath

def swap_extensions(dir,before,after):
if before[:1] != '.':   #如果参数后缀没有’.'则加上
before='.'+before
thelen = -len(before)
if after[:1] != '.':
after = '.'+after
for dirpath,dirnames,filenames in os.walk(path):
for oldfile in filenames:
if oldfile[thelen:] == before:
oldfile = os.path.join(path,oldfile)
newfile = oldfile[:thelen]+after
os.rename(oldfile,newfile)
print oldfile+' changed to '+newfile

if __name__ == '__main__':
import sys
if len(sys.argv) != 4:
print 'Usage:swap_extension.py rootdir before after'
sys.exit(1)
swap_extensions(sys.argv[1],sys.argv[2],sys.argv[3])