Python对文件修改，替换，删除

一、修改原文件内容方式：

1#!/usr/bin/env python
2# -*- coding:utf8 -*-
3
4
5old_str = "aaa" #老文件内容字段
6new_str = "bbb" #要改成字段
7file_data = ''
8with open('/opt/1.txt', 'r', encoding='utf-8') as f:
9    for line in f:
10        if old_str in line:
11            line = line.replace(old_str, new_str)
12            file_data += line
13with open('/opt/1.txt', 'w',encoding='utf-8') as f:
14    f.write(file_data)

二、python 使用正则表达式 替换文件内容 re.sub 方法替换

1import re,os
2def alter(file,old_str,new_str):
3
4    with open(file, "r", encoding="utf-8") as f1,open("%s.bak" % file, "w", encoding="utf-8") as f2:
5        for line in f1:
6            f2.write(re.sub(old_str,new_str,line))
7    os.remove(file)
8    os.rename("%s.bak" % file, file)
9alter("file1", "admin", "password")

三、python 删除文件一行

1import shutil
2with open('/path/to/file', 'r') as f:
3    with open('/path/to/file.new', 'w') as g:
4        for line in f.readlines():
5            if '/local/server' not in line:             
6                g.write(line)
7shutil.move('/path/to/file.new', '/path/to/file')