'''import os
file_num=0
for root, dirs, files in os.walk("e:\\asd",topdown=False) :
for name in files :
if ".txt" == name[-4:]: #方法2if ".txt" in name: #方法3 if name.find(".txt")!=-1:
file_num+=1
print file_num'''
'''import os
file_num=0
for root, dirs, files in os.walk("e:\\asd",topdown=False) :
for name in files :
if ".txt" == name[-4:]: #方法2if ".txt" in name: #方法3 if name.find(".txt")!=-1:
file_num+=1
print file_num'''