擅长:python、mysql、java
<p>将<code>date</code>列设置为索引,然后过滤出<code>type</code>所在的位置<code>baseline</code>,然后使用<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.div.html" rel="nofollow noreferrer">^{<cd4>}</a></p>
<pre><code>_df = df.set_index('date')
d = _df.query('type=="baseline"') # same as _df.loc[_df['type'].eq('baseline')]
df['score_ratio'] = _df['score'].div(d['score']).values
df
date type score score_ratio
0 20201101 experiment1 30 3.0
1 20201101 experiment2 20 2.0
2 20201101 baseline 10 1.0
3 20201102 experiment1 60 6.0
4 20201102 experiment2 50 5.0
5 20201102 baseline 10 1.0
</code></pre>