擅长:python、mysql、java
<p>更快的方法:</p>
<pre><code>In [58]: df['sugar_content'] = df.reset_index()['fruit'].map(sugar_content).to_frame().set_index(df.index)
In [59]: df
Out[59]:
Quantity sugar_content
basket fruit
Tom apple 1 3
banana 2 10
Anna banana 3 10
citrus 4 2
</code></pre>
<p>说明:</p>
<pre><code>In [60]: df.reset_index()['fruit'].map(sugar_content)
Out[60]:
0 3
1 10
2 10
3 2
Name: fruit, dtype: int64
In [61]: df.reset_index()['fruit'].map(sugar_content).to_frame()
Out[61]:
fruit
0 3
1 10
2 10
3 2
In [62]: df.reset_index()['fruit'].map(sugar_content).to_frame().set_index(df.index)
Out[62]:
fruit
basket fruit
Tom apple 3
banana 10
Anna banana 10
citrus 2
</code></pre>