擅长:python、mysql、java
<p>这里有必要按列<code>Job Number</code>使用<code>map</code>,而不是<code>Customer</code>:</p>
<pre><code>df['Customer'] = df['Customer'].combine_first(df['Job Number'].map(customers))
print (df)
Job Number Customer
0 2123 Paul F
1 46456 Kara L
2 56823 Kevin T
3 62948 Sabrina M
</code></pre>
<p><strong>详细信息</strong>:</p>
<pre><code>print (df['Job Number'].map(customers))
0 NaN
1 Kara L
2 NaN
3 Sabrina M
Name: Job Number, dtype: object
</code></pre>