擅长:python、mysql、java
<p>尝试使用:</p>
<pre><code>print(foodList.set_index('food_name').mul(foodConversions.reindex(foodList['food_name'])['cal/gram'], axis=0).reset_index())
</code></pre>
<p>输出:</p>
<pre><code> food_name food_quant
0 meat 80
1 meat 60
2 vegetables 60
3 meat 20
</code></pre>