擅长:python、mysql、java
<p><code>map</code>在一个唯一键上进行连接就足够了:</p>
<pre><code>d = {**df1.set_index('ClientName').CLientNumber,
**df2.set_index('ClientName').CLientNumber}
df0['ClientNumber'] = df0['ClientName'].map(d)
</code></pre>
<hr/>
<pre><code> ClientName City State ClientNumber
0 JohnSmith Dallas TX 100
1 JaneDoe Dallas TX 101
2 LucasAult Dallas TX 102
3 CarsonSeibert Dallas TX 103
</code></pre>