擅长:python、mysql、java
<p>我想你想要这个:</p>
<pre><code>dfm['D'] = dfm[['A', 'B', 'C']].apply(lambda x: ','.join(a for a in x if a), axis=1)
</code></pre>
<p>输出:</p>
<pre><code> A B C D
0 apple pear apple,pear
1 orange apple orange,apple
2 grape grape
</code></pre>