擅长:python、mysql、java
<p>使用理解列表,您可以:</p>
<pre><code>df['refValue'] = [ row['Value'] - float(df.loc[(df['No']==row['No']) & (df['Group']==row['refGroup']),'Value'].values) if row['refGroup']!=row['Group'] else row['Value'] for index, row in df.iterrows() ]
</code></pre>