擅长:python、mysql、java
<p>像这样:</p>
<pre><code>with open("input.txt") as f,open("output.txt","w") as f2:
for line in f: #iterate over each line of input.txt
if ";cr;" in line: #if ';cr;' is found
f2.write(line+'\n') #then write that line to "output.txt"
</code></pre>
<p>在python中,可以使用<code>in</code>轻松检查子字符串:</p>
^{pr2}$