<p>当使用<code>drop_duplicates()</code>方法时,我减少了重复项,但也将所有<code>NaNs</code>合并到一个条目中。如何在保留空条目的行(如<code>np.nan, None or ''</code>)时删除重复项?</p>
<pre><code>import pandas as pd
df = pd.DataFrame({'col':['one','two',np.nan,np.nan,np.nan,'two','two']})
Out[]:
col
0 one
1 two
2 NaN
3 NaN
4 NaN
5 two
6 two
df.drop_duplicates(['col'])
Out[]:
col
0 one
1 two
2 NaN
</code></pre>
<p>试试看</p>
<pre><code>df[(~df.duplicated()) | (df['col'].isnull())]
</code></pre>
<p>结果是:</p>
<pre><code>col
0 one
1 two
2 NaN
3 NaN
4 NaN
</code></pre>