擅长:python、mysql、java
<p>IUC,你可以做<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.stack.html" rel="nofollow noreferrer">^{<cd1>}</a>和<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.merge.html" rel="nofollow noreferrer">^{<cd2>}</a>:</p>
<pre><code>final=(Flight_df.merge(WCat_df.stack().reset_index(1,name='AC-Cat'),on='AC-Cat',how='left')
.rename(columns={'level_1':'New'}))
print(final)
</code></pre>
<p>或使用<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.melt.html" rel="nofollow noreferrer">^{<cd3>}</a>:</p>
<pre><code>final=Flight_df.merge(WCat_df.melt(var_name='New',value_name='AC-Cat'),
on='AC-Cat',how='left')
</code></pre>
<hr/>
<pre><code> AC-Cat Origin New
0 B737 AJD CAT-D
1 A320 JFK CAT-D
2 MD11 LRO CAT-C
</code></pre>