使用python开发类似于sed功能，实现替换功能

Dear 丶 2022-06-02 12:29 163阅读 0赞

使用python开发类似于sed功能，实现替换功能  
  
\#!/usr/bin/env python  
\#\_\*\_ coding:utf-8 \_\*\_  
import sys,os  
  
if len(sys.argv) <= 4:  
    print "Usage: ./file\_replace.py old\_text new\_text filename"  
old\_text,new\_text = sys.argv\[1\],sys.argv\[2\]  
  
file\_name = sys.argv\[3\]            
\#打开文件  
f = file(file\_name,'rb')    
\#打开一个新的文件     
new\_file = file('.%s.bak' % file\_name,'wb')  
\#循环原文件  
for line in f.xreadlines():  
    \#写然后替换  
    new\_file.write(line.replace(old\_text,new\_text))  
f.close()  
new\_file.close()  
  
if '--bak' in sys.argv:  
    \#unchanged  
    os.rename(file\_name,'%s.bak' %file\_name)   
    \#changed      
    os.rename('.%s.bak' %file\_name,file\_name)  
else:  
    \#replace  
    os.rename('.%s.bak' %file\_name,file\_name)  
  
\[root@node01 python\]\# python file\_replace.py : '|' passwd    修改成功  
\[root@node01 python\]\#cat passwd  
wolf01|x|502|502||/home/wolf01|/bin/bash  
wolf02|x|503|503||/home/wolf02|/bin/bash  
wolf03|x|504|504||/home/wolf03|/bin/bash  
wolf04|x|505|505||/home/wolf04|/bin/bash  
wolf05|x|506|506||/home/wolf05|/bin/bash  
wolf06|x|507|507||/home/wolf06|/bin/bash  
wolf07|x|508|508||/home/wolf07|/bin/bash  
wolf08|x|509|509||/home/wolf08|/bin/bash  
wolf09|x|510|510||/home/wolf09|/bin/bash  
wolf10|x|511|511||/home/wolf10|/bin/bash      
\[root@node01 python\]\# python file\_replace.py '|' ":" passwd  --bak  
\[root@node01 python\]\#cat passwd  
wolf01:x:502:502::/home/wolf01:/bin/bash  
wolf02:x:503:503::/home/wolf02:/bin/bash  
wolf03:x:504:504::/home/wolf03:/bin/bash  
wolf04:x:505:505::/home/wolf04:/bin/bash  
wolf05:x:506:506::/home/wolf05:/bin/bash  
wolf06:x:507:507::/home/wolf06:/bin/bash  
wolf07:x:508:508::/home/wolf07:/bin/bash  
wolf08:x:509:509::/home/wolf08:/bin/bash  
wolf09:x:510:510::/home/wolf09:/bin/bash  
wolf10:x:511:511::/home/wolf10:/bin/bash  
\[root@node01 python\]\# ll |grep passwd         生成了一个bak文件  
\-rw-r--r-- 1 root root 2257 Aug 18 04:00 passwd  
\-rw-r--r-- 1 root root 2257 Aug 18 03:55 passwd.bak  
\[root@node01 python\]\#\#cat passwd.bak          bak文件未修改  
wolf01|x|502|502||/home/wolf01|/bin/bash  
wolf02|x|503|503||/home/wolf02|/bin/bash  
wolf03|x|504|504||/home/wolf03|/bin/bash  
wolf04|x|505|505||/home/wolf04|/bin/bash  
wolf05|x|506|506||/home/wolf05|/bin/bash  
wolf06|x|507|507||/home/wolf06|/bin/bash  
wolf07|x|508|508||/home/wolf07|/bin/bash  
wolf08|x|509|509||/home/wolf08|/bin/bash  
wolf09|x|510|510||/home/wolf09|/bin/bash  
wolf10|x|511|511||/home/wolf10|/bin/bash