擅长:python、mysql、java
<p>你可以这样做:</p>
<pre><code>df.B.add(df.C).ne(df.D).sum()
# 3
</code></pre>
<hr/>
<p>如果需要添加列:</p>
<pre><code>df['B+C'] = df.B.add(df.C)
diff = df['B+C'].ne(df.D).sum()
print(f'There are {diff} different values compare the "B+C" and "D"')
#There are 3 different values compare the "B+C" and "D"
</code></pre>