Вот пример:
import numpy as np
import pandas as pd
In[3]:
mtx = np.random.randn(10)
mtx
Out[3]:
array([-1.47694909, -0.61658367, -1.2609941 , 0.33956725, 1.69096661,
0.10680407, -3.53473223, 0.61587513, 2.34405466, -1.49556778])
In[4]:
ser = pd.Series(mtx)
ser
Out[4]:
0 -1.476949
1 -0.616584
2 -1.260994
3 0.339567
4 1.690967
5 0.106804
6 -3.534732
7 0.615875
8 2.344055
9 -1.495568
dtype: float64
In[5]:
ser.idxmax()
Out[5]:
8
In[6]:
ser[ser.idxmax()]
Out[6]:
2.344054659817029