txt文件每行内容与图片文件名字组合，输出txt格式

import os


dir_list = os.listdir('C:\Users\10107472\Desktop\practice\JPEGImages')
i=0
f1=open('C:\Users\10107472\Desktop\practice\train1.txt','r')
f2=open('C:\Users\10107472\Desktop\practice\train.txt','w')
# f3=open('C:\Users\10107472\Desktop\practice\train.txt','w')
line=f1.readline()
line=line[:-1]
while line:
    line = f1.readline()
    line = line[:-1]

    f2.write(k+dir_list[i]+' '+line[49:])
    f2.write('
')

    i=i+1
    if i>800:
        break
f1.close()