擅长:python、mysql、java
<p>如果文件很小,那么您只需使用<code>str.replace()</code>:</p>
<pre><code>>>> !cat abc.txt
xxxxx
yyyyy
zzzzz
ttttt
>>> with open("abc.txt") as f,open("out.txt",'w') as o:
data=f.read()
data=data.replace("xxxxx\nyyyyy","xxxxx\nyourline\nyyyyy")
o.write(data)
....:
>>> !cat out.txt
xxxxx
yourline
yyyyy
zzzzz
ttttt
</code></pre>
<p>对于一个大文件,使用mgilson的方法。</p>