擅长:python、mysql、java
<p>我想你在寻找:</p>
<pre><code>df['mean'] = df.groupby('Animal')['Max Speed'].mean()
</code></pre>
<p>这里可能还值得一看变量命名约定:<a href="https://www.python.org/dev/peps/pep-0008/" rel="nofollow noreferrer">https://www.python.org/dev/peps/pep-0008/</a></p>