擅长:python、mysql、java
<p>使用<code>dt.year</code>怎么样</p>
<pre><code>new_df = df.groupby([df["effectiveDate"].dt.year, df["itemId"]])["sellerId"].agg(list).to_frame()
print(new_df)
sellerId
effectiveDate itemId
2005 1975245 2585893 [31280]
2006 1975246 2585893 [31280]
1975247 2585893 [5407]
1975248 2585893 [5407]
1975249 2585893 [5407]
1975250 2585893 [5407]
2007 1975254 2585893 [5407]
1975257 2585893 [5407]
1975258 2585893 [5407]
2008 1975259 2585893 [5407]
</code></pre>