擅长:python、mysql、java
<p>对于您的用例,您需要使用groupby:</p>
<pre><code>dupes = df_attachment.groupby('Name').ID.count() > 1
dupes.name = 'Duplicate'
#merge duplicate flage into the original dataframe on the common column 'Name'
df_attachment = pd.merge(df_attachment, dupes.reset_index())
</code></pre>