Python文件操作中进行字符串替换的方法（保存到新文件/当前文件）_Python

Python文件操作中进行字符串替换的方法（保存到新文件/当前文件）

2021-07-26 00:20A72HONGJIE Python

这篇文章主要介绍了Python文件操作中进行字符串替换的方法（保存到新文件/当前文件） ,本文给大家介绍两种方法，每种方法给大家介绍的非常详细，具有一定的参考借鉴价值，需要的朋友可以参考下

题目：

1.首先将文件：/etc/selinux/config 进行备份文件名为 /etc/selinux/config.bak

2.再文件：/etc/selinux/config 中的enforcing 替换为 disabled

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									# This file controls the state of SELinux on the system.

									# SELINUX= can take one of these three values:

									#   enforcing - SELinux security policy is enforced.

									#   permissive - SELinux prints warnings instead of enforcing.

									#   disabled - No SELinux policy is loaded.

									SELINUX=disabled

									# SELINUXTYPE= can take one of three two values:

									#   targeted - Targeted processes are protected,

									#   minimum - Modification of targeted policy. Only selected processes are protected. 

									#   mls - Multi Level Security protection.

									SELINUXTYPE=enforcing

•方法一：用replace

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									import os

									import shutil

									def selinux_config():

									  """

									  关闭SELINUX

									  修改文件内容

									  :return:

									  """

									  file_selinux = '/etc/selinux/config'

									  backup_file_selinux = file_selinux + '.bak'

									  temp_file_selinux = file_selinux + '.temp'

									  if not os.path.exists(backup_file_selinux):

									    shutil.copy2(file_selinux, backup_file_selinux)

									    with open(file_selinux, mode='r') as fr, open(temp_file_selinux, mode='w') as fw:

									      origin_line = 'SELINUX=enforcing'

									      update_line = 'SELINUX=disabled'

									      for line in fr:

									        fw.write(line.replace(origin_line, update_line))

									    os.remove(file_selinux)

									    os.rename(temp_file_selinux, file_selinux)

									if __name__ == '__main__':

									  selinux_config()

•方法二：用re.sub

				?

									#! /usr/bin/env python

									# -*- coding: utf-8 -*-

									import os

									import re

									import shutil

									def selinux_config():

									  """

									  关闭SELINUX

									  修改文件内容

									  :return:

									  """

									  file_selinux = '/etc/selinux/config'

									  backup_file_selinux = file_selinux + '.bak'

									  temp_file_selinux = file_selinux + '.temp'

									  if not os.path.exists(backup_file_selinux):

									    shutil.copy2(file_selinux, backup_file_selinux)

									    with open(file_selinux, mode='r') as fr, open(temp_file_selinux, mode='w') as fw:

									      origin_line = 'SELINUX=enforcing'

									      update_line = 'SELINUX=disabled'

									      for line in fr:

									        re_sub_list = re.sub(origin_line, update_line, line) # 这里用re.sub进行替换后放入 re_sub_list中

									        fw.writelines(re_sub_list) # 将列表中的每一行进行写入。writelines是将序列对象中的每一行进行写入。

									    os.remove(file_selinux)

									    os.rename(temp_file_selinux, file_selinux)

									if __name__ == '__main__':

									  selinux_config()