<p>同样的想法也可以用lambda函数来实现。
在这里,我从xlsx文件中读取数据。</p>
<pre><code>import pandas as pd
df = pd.read_excel("data.xlsx", sheet_name = 4)
print df
</code></pre>
<p>输出:</p>
<pre><code> cluster Unnamed: 1 date budget actual
0 a 2014-01-01 00:00:00 11000 10000
1 a 2014-02-01 00:00:00 1200 1000
2 a 2014-03-01 00:00:00 200 100
3 b 2014-04-01 00:00:00 200 300
4 b 2014-05-01 00:00:00 400 450
5 c 2014-06-01 00:00:00 700 1000
6 c 2014-07-01 00:00:00 1200 1000
7 c 2014-08-01 00:00:00 200 100
8 c 2014-09-01 00:00:00 200 300
</code></pre>
<p>把两列加在第三列。</p>
<pre><code>df['variance'] = df.apply(lambda x: x['budget'] + x['actual'], axis=1)
print df
</code></pre>
<p>输出:</p>
<pre><code> cluster Unnamed: 1 date budget actual variance
0 a 2014-01-01 00:00:00 11000 10000 21000
1 a 2014-02-01 00:00:00 1200 1000 2200
2 a 2014-03-01 00:00:00 200 100 300
3 b 2014-04-01 00:00:00 200 300 500
4 b 2014-05-01 00:00:00 400 450 850
5 c 2014-06-01 00:00:00 700 1000 1700
6 c 2014-07-01 00:00:00 1200 1000 2200
7 c 2014-08-01 00:00:00 200 100 300
8 c 2014-09-01 00:00:00 200 300 500
</code></pre>