You could convert your series
to a dataframe
using reset_index()
and provide name="yout_col_name"
— The name of the column corresponding to the Series values
(df_grp.apply(lambda x: x['C'].sum() * x['D'].mean() / x['E'].max())
.reset_index(name="your_col_name"))
A B your_col_name
0 X N 5.583333
1 Y M 2.975000
2 Y N 3.845455