Python，遍历目录下TXT

import os
#获取根目录，递归得到所以txt文件的路径
list_dirs = os.walk(os.curdir)
txtfilenames=[]
for root, dirs, files in list_dirs:
# for d in dirs:
#     print os.path.join(root, d)
filenames=filter(lambda filename:filename[-4:]=='.txt',filenames)
filenames=map(lambda filename:os.path.join(root,filename),filenames)
txtfilenames.extend(filenames)