python 读取全部文件名以及路径，并且输出到txt

import os
txtName = "test.txt"
f=file(txtName, "a+")
dire="/media/tina/ET/caffe/SegNet_ip/CamVid/test/"
anchor="/media/tina/ET/caffe/SegNet_ip/CamVid/testannot/"
for root ,dirs, files in os.walk(dire):
    for file_single in files:
        test = dire+file_single
        refile = file_single[0:8]
        anchort = anchor + refile +'.png'
        result = test + " " +anchort +'\n'
        f.write( result)
f.close()