擅长:python、mysql、java
<p>只需使用<code>split()</code></p>
<pre><code>for line in file_B:
t = line.split('.') this splits string in collection
outfile.write(t[0]) first variable from collection
</code></pre>
<p>更新:对于文件\u B中但不在文件\u A中的行:</p>
<pre><code>for line in file_B:
t = line.split('.')
target = t[0]
if target not in file_A:
outfile.write(target)
</code></pre>
<p>更新:仅适用于文件\u B中也在文件\u A中的行:</p>
<pre><code>for line in file_B:
t = line.split('.')
target = t[0]
if target in file_A:
outfile.write(target)
</code></pre>