PYTHON

pandas sum multiple columns groupby

df.groupby(['col1','col2']).agg({'col3':'sum','col4':'sum'}).reset_index()

python groupby sum single columns

df.groupby(['A','C'], as_index=False)['B'].sum()

pandas sum multiple columns groupby

#UPDATED (June 2020): Introduced in Pandas 0.25.0, 
#Pandas has added new groupby behavior “named aggregation” and tuples, 
#for naming the output columns when applying multiple aggregation functions 
#to specific columns.

df.groupby(
     ['col1','col2']
 ).agg(
     sum_col3 = ('col3','sum'),
     sum_col4     = ('col4','sum'),
 ).reset_index()