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('\n')

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