擅长:python、mysql、java
<p>使用<code>%</code>:</p>
<pre><code>for index, line in enumerate(my_file.readlines()):
if (index + 1) % 3 == 1: # means lines 1, 4 ,7, 10..
# write line to file1
elif (index + 1) % 3 == 2: # means lines 2, 5 ,8..
# write line to file2
else: # means lines 3, 6, 9
# write line to file3
</code></pre>