Here, You can test the max value using the index returned, indices returned should look like (array([0], dtype=int64), array([2], dtype=int64)) when you print the indices.
import numpy as np
a = np.array([[200,300,400],[100,50,300]])
indices = np.where(a == a.max())
print(a[indices]) # prints [400]
# Index for max value found two times (two locations)
a = np.array([[200,400,400],[100,50,300]])
indices = np.where(a == a.max())
print(a[indices]) # prints [400 400] because two indices for max
#Now lets print the location (Index)
for index in indices:
print(index)
