擅长:python、mysql、java
<p>你也可以一次完成,先排序,然后用head取每组的前3个。</p>
<pre><code>In[34]: df.sort_values(['job','count'],ascending=False).groupby('job').head(3)
Out[35]:
count job source
4 7 sales E
2 6 sales C
1 4 sales B
5 5 market A
8 4 market D
6 3 market B
</code></pre>