Answers for "how to sum many column and groupby"

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()

sum group by pandas and create new column

df['new_column'] = df.groupby(['group_column'])['sum_column'].transform('sum')