擅长:python、mysql、java
<p>这不是单行代码,但可能有用</p>
<pre><code># First, group by 'Type' and sum 'No'
df_group = df.groupby(['Type'], as_index=False)['No'].sum().rename(columns={'No': 'Sum'})
# Second, merge by 'Type'
df.merge(df_group, how='left', left_on='Type', right_on='Type')
</code></pre>