python文件修改

import os
os.remove("emm.txt")

把原内容读取出来修改

修改后放进创建的副本文件

删除原文件

重命名副本

#首先创建一个文件
import os

with open("张冠李戴.txt", mode = "w", encoding = "utf-8") as f:
    f.write("李小龙n成龙n成小玉n李嘉诚n周星驰n李世民n周杰伦n李靖n")

#把姓李的改成姓周的
with open("张冠李戴.txt", mode = "r", encoding = "utf-8") as f1, 
     open("张冠李戴_副本.txt", mode = "w", encoding = "utf-8") as f2:
    for line in f1:
        line = line.strip()
        if line.startswith("李"):
            line = line.replace("李","张")
        f2.write(line)
        f2.write("n")

os.remove("张冠李戴.txt")
os.rename("张冠李戴_副本.txt","张冠李戴.txt")

张小龙
成龙
成小玉
张嘉诚
周星驰
张世民
周杰伦
张靖