numpy array print index of certain value

Question

Given a numpy array

A = np.array([[[29, 64, 83],
               [17, 92, 38],
               [67, 34, 20]],
              [[73, 28, 45],
               [19, 84, 61],
               [22, 63, 49]],
              [[48, 30, 13],
               [11, 52, 86],
               [62, 25, 12]]])

I want the index of a certain value, say 63

There is no possibility that the value will be duplicated or missing

I did

idx = np.where(A == 63)

print(idx)

I got

(array([1], dtype=int32), array([2], dtype=int32), array([1], dtype=int32))

What I want is

[1, 2, 1]

as a list or other iterable without all that array, dtype=int32 etc.

How do I do this?

Answer 1

If you want to get a numpy array back, just use the concatenate function:

In [30]: np.concatenate(idx)
Out[30]: array([1, 2, 1])

If you really have your heart set on a Python list, then just:

In [31]: np.concatenate(idx).tolist()
Out[31]: [1, 2, 1]