擅长:python、mysql、java
<p>我们可以做<code>reindex</code>或<code>loc</code>或<code>map</code>或<a href="https://stackoverflow.com/questions/53645882/pandas-merging-101">^{<cd4>}</a></p>
<p><code>reindex|loc</code></p>
<pre><code>df2.assign(food_quant=df2.food_quant*(df1['cal/gram'].reindex(df2.food_name).values))# change reindex to loc
Out[121]:
food_name food_quant
0 meat 80
1 meat 60
2 vegetables 60
3 meat 20
</code></pre>
<p><code>map|replace</code></p>
<pre><code>df2.assign(food_quant=df2.food_quant*df2.food_name.map(df1['cal/gram']))
df2.assign(food_quant=df2.food_quant*df2.food_name.replace(df1['cal/gram']))
</code></pre>