擅长:python、mysql、java
<p><a href="http://docs.python.org/2/library/stdtypes.html#file.writelines" rel="nofollow">http://docs.python.org/2/library/stdtypes.html#file.writelines</a></p>
<pre><code>with open('bed-interval') as f1, open('bed-interval-modified', 'w') as f2:
f2.writelines('chr' + line for line in f1)
</code></pre>