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)