将pandas数据框中的两列求和

我认为您已经误解了某些python语法，以下代码执行了两项任务：

In [11]: a = b = 1In [12]: aOut[12]: 1In [13]: bOut[13]: 1

因此，在您的代码中就好像您在做的一样：

sum = df['budget'] + df['actual']  # a Series# anddf['variance'] = df['budget'] + df['actual']  # assigned to a column

后者为df创建了一个新列：

In [21]: dfOut[21]:  cluster      date  budget  actual0       a  2014-01-01 00:00:00   11000   100001       a  2014-02-01 00:00:00    1200    10002       a  2014-03-01 00:00:00     200     1003       b  2014-04-01 00:00:00     200     3004       b  2014-05-01 00:00:00     400     4505       c  2014-06-01 00:00:00     700    10006       c  2014-07-01 00:00:00    1200    10007       c  2014-08-01 00:00:00     200     1008       c  2014-09-01 00:00:00     200     300In [22]: df['variance'] = df['budget'] + df['actual']In [23]: dfOut[23]:  cluster      date  budget  actual  variance0       a  2014-01-01 00:00:00   11000   10000     210001       a  2014-02-01 00:00:00    1200    1000      22002       a  2014-03-01 00:00:00     200     100       3003       b  2014-04-01 00:00:00     200     300       5004       b  2014-05-01 00:00:00     400     450       8505       c  2014-06-01 00:00:00     700    1000      17006       c  2014-07-01 00:00:00    1200    1000      22007       c  2014-08-01 00:00:00     200     100       3008       c  2014-09-01 00:00:00     200     300       500

顺便

sum