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)