4.实现简单的shell sed替换功能 

 1 # -*- coding:utf-8 -*-
 2 # Author: JACK ZHAO
 3 
 4 # 程序1: 实现简单的shell sed替换功能
 5 
 6 import  sys
 7 
 8 #判断参数个数
 9 if len(sys.argv) != 3:
10     print("Usage: python_sed.py 'old string' 'net string'")
11     exit()
12 #读取所有行至内存中
13 with open("yesterday","r",encoding='utf-8') as f:
14     lines = f.readlines()
15 
16 #重新生成文件yesterday,读取内存中内容至新文件
17 with open("yesterday","w",encoding='utf-8') as f:
18     for line in lines:
19         if sys.argv[1] in line:
20             line = line.replace(sys.argv[1],sys.argv[2]) #sys.argv[1]:要替换的内容 sys.argv[2]:替换后的内容
21         f.write(line)

 

posted on 2017-11-16 15:55  ChangMingZhao  阅读(193)  评论(0)    收藏  举报

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