In [6]:
import numpy as np
a = np.random.randint(20,size=20)
a


Out[6]:
array([11, 13, 12,  0, 14,  0,  1,  8,  6,  7,  0,  6,  9, 12, 19, 16,  6,
       11,  4, 15])

In [10]:
a.tolist().index(max(a))


Out[10]:
14

In [12]:
a = [1,2,3,3]
a.index(max(a))


Out[12]:
2

In [ ]: