how to do sum in pandas? code example

Example 1: pandas sum

df.loc['Total'] = pd.Series(df['MyColumn'].sum(), index = ['MyColumn'])
print (df)
         X  MyColumn      Y      Z
0        A      84.0   13.0   69.0
1        B      76.0   77.0  127.0
2        C      28.0   69.0   16.0
3        D      28.0   28.0   31.0
4        E      19.0   20.0   85.0
5        F      84.0  193.0   70.0
Total  NaN     319.0    NaN    NaN

Example 2: pandas sum

import pandas as pd

data = {'Month': ['Jan ','Feb ','Mar ','Apr ','May ','Jun '],
        'Bill Commission': [1500,2200,3500,1800,3000,2800],
        'Maria Commission': [3200,4100,2500,3000,4700,3400], 
        'Jack Commission': [1700,3100,3300,2700,2400,3100]
        }

df = pd.DataFrame(data,columns=['Month','Bill Commission','Maria Commission','Jack Commission'])
print (df)