擅长:python、mysql、java
<p>可以使用numpy<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.where.html" rel="nofollow noreferrer">^{<cd1>}</a>按以下方式更新列:</p>
<pre><code>import pandas as pd
import numpy as np
df1 = pd.DataFrame({'UniqueKey': ['A', 'B','C','D','E'], 'ValueFix': [10,15,20,15,10], 'ValueChange': [100,0,150,0,100]})
df2 = pd.DataFrame({'UniqueKey': ['B', 'D'], 'ValueFix': [15,15], 'ValueChange': [300,400]})
merged_df = df1.merge(df2, on='UniqueKey', how='left')
df1.ValueChange = np.where(df1.UniqueKey.isin(df2.UniqueKey), merged_df.ValueChange_y, merged_df.ValueChange_x)
</code></pre>
<p>输出为</p>
<pre><code>print(df1)
UniqueKey ValueFix ValueChange
0 A 10 100.0
1 B 15 300.0
2 C 20 150.0
3 D 15 400.0
4 E 10 100.0
</code></pre>