擅长:python、mysql、java
<p>尝试:</p>
<pre><code>output = df.groupby("store_id") \
.apply(lambda x: x.nlargest(2, "amount")["item"].tolist()) \
.rename(index="item")
>>> output
store_id
00001 [shirt, sock]
00002 [sock, pants]
Name: item, dtype: object
</code></pre>