擅长:python、mysql、java
<p>我不确定是否有效率,但它是有效的:</p>
<pre class="lang-py prettyprint-override"><code>k = 3 # every k column
pd.DataFrame([df.values[:,[n,n+k,n+k]].flatten() for n in range(k)]).T
0 1 2
0 A B C
1 A B C
2 A B C
3 D E F
4 D E F
5 D E F
</code></pre>