如何通过值选择行-将其设置为标题行-在python中删除该值之前的所有行？

with open('file.txt', 'r') as file:
    lines = file.readlines()

target_value = '目标值'
title_index = None

for i, line in enumerate(lines):
    if target_value in line:
        title_index = i
        break

lines[0], lines[title_index] = lines[title_index], lines[0]

lines = lines[title_index:]

with open('file.txt', 'w') as file:
    file.writelines(lines)