idxmax() doesn't work on SeriesGroupBy that contains NaN

Question

Here is my code

from pandas import DataFrame, Series
import pandas as pd
import numpy as np
income = DataFrame({\'name\': [\'Adam\', \'Bill\', \'Chris\', \'Dave\         


        

Answer 1

grouped['income'].agg(lambda x : x.idxmax())


Out[]:
age
(20, 30]     1
(30, 40]   NaN
(40, 50]     2
(50, 60]     4
Name: income, dtype: float64

and then you can do the following to get the data

income.ix[result.values].dropna()