擅长:python、mysql、java
<p>我想你在找<code>isin</code>:</p>
<pre><code># you can use `loc` to access `new_cases` also
days = [4, 5, 6]
df.loc[df.weekday.isin(days), "new_cases"].mean()
</code></pre>
<p>选择<code>weekday</code>在<code>days</code>列表中的行;然后选择<code>new_cases</code>列</p>