pandas dataframe 中特定列的总和

Question

Consider I have a dataframe with few columns

and a list ['salary','gross exp']

Now I want to perform sum of the column operation only on the columns from the list on the dataframe and save that to the dataframe

To put this in prespective, the list of columns ['salary','gross exp'] are money related and it makes sense to perform sum on these columns and not touch any of the other columns

PS: I have several Excel workbooks to work on and each consists of few tens of sheets, so doing it manually is out of options

Also macro code for excel works fine if that's possible

TIA

Answer 1

Working with the following example:

import pandas as pd

list_ = ['sallary', 'gross exp']
d = {'sallary': [1,2,3], 'gross exp': [2,2,2], 'another column': [10,10,10]}
df = pd.DataFrame(d)
df

	sallary	gross exp	another column
0	1	2	10
1	2	2	10
2	3	2	10

You can then add a new empty row, and insert the sum of the columns that you have from the list in that same row:

df = df.append(pd.Series(dtype = float), ignore_index=True)
df.loc[df.index[-1],list_] = df[list_].sum()
df

	sallary	gross exp	another column
0	1.0	2.0	10.0
1	2.0	2.0	10.0
2	3.0	2.0	10.0
3	6.0	6.0	NaN