python脚本修改hosts文件

　　用python3写了个修改hosts的小脚本，没有技术含量，顺带复习一下文件操作和os、sys模块的内容了。

# -*- coding:utf-8 -*-
#!/usr/bin/env python
# @Author  : tianbao
# @Contact : [e-mail]
# @Time    : 2018/4/5 17:06
# @File    : change_host_file.py
# @Software: PyCharm
'''
使用说明：
    PATH :HOSTS文件路径
    NEW_PATH :新HOSTS文件路径

    在change_host_file.py所在目录打开cmd运行以下命令
                                     方法   IP        网址
    添加：python change_host_file.py add 8.8.8.8 www.google.com
    删除：python hange_host_file.py del 126.125.66.198   删除整行
    修改：python hange_host_file.py change www.cnblogs.com www.google.com
                                                 old              new
'''
import sys,os,re

PATH = 'G:\jiaoben\HOSTS'
NEW_PATH = 'G:\jiaoben\HOSTS_NEW'
def run():
    try:
        if sys.argv[1] == 'add':
            with open(PATH,'a+',encoding='utf-8') as f:
                new_IP = sys.argv[2] + ' '+ sys.argv[3]
                f.write('\n')
                f.write(new_IP)
                sys.exit('添加成功，请查看源文件')
        elif sys.argv[1] == 'del':
            with open(PATH, 'r+', encoding='utf-8') as f,open(NEW_PATH, 'a+', encoding='utf-8') as f2:
                data = f.readlines()
                for line in data:
                    if sys.argv[2] in line:
                        continue
                    f2.write(line)
            os.remove(PATH)
            os.rename(NEW_PATH,PATH)
            sys.exit('删除成功，请查看源文件')
        elif sys.argv[1] == 'change':
            open(NEW_PATH, 'a+').write(re.sub(r'%s'% sys.argv[2],'%s'% sys.argv[3],open(PATH).read()))
            os.remove(PATH)
            os.rename(NEW_PATH,PATH)
            sys.exit('修改成功，请查看源文件')
    except Exception as e:
        print(e)
if __name__ == '__main__':
    run()