擅长:python、mysql、java
<p>一个选项是合并ID上的两个dfs,然后计算差异:</p>
<pre><code>df_a = df_a.merge(df_b.drop(['Time'], axis=1), on="ID", suffixes=['', '2'])
df_a['Diff'] = df_a['Volume'] - df_a['Volume2']
</code></pre>
<p>df:</p>
<pre><code> Time Volume ID Volume2 Diff
0 1 5 1 3 2
1 2 6 2 2 4
2 3 7 3 4 3
</code></pre>