df.groupby(['Fruit','Name'])['Number'].sum()
df['new_column'] = df.groupby(['group_column'])['sum_column'].transform('sum')
df.groupby(['att1', 'att2']).agg({'att1': "count", 'att3': "sum",'att4': 'mean'})
df.groupby(['Fiscal_Year','Billing_Group'])['CHARGE_AMT'].sum()