擅长:python、mysql、java
<p>也可以用下面提到的方法完成(不使用<a href="http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.duplicated.html" rel="nofollow noreferrer">Series.duplicated</a>):</p>
<pre><code>dictionary = df[['Id','Policy_id']].set_index('Policy_id').to_dict()['Id']
#here the dictionary values contains the most recent Id's
df['Last_dup'] = df.Id.apply(lambda x: 1 if x in list(dictionary.values()) else 0)
</code></pre>