Is there a way to get a list or array of all indices in an N-dimensional array in a fast and efficient way in Python?

For example, image we have the following array:

```
import numpy as np

test = np.zeros((4,4))

array([[0., 0., 0., 0.],
       [0., 0., 0., 0.],
       [0., 0., 0., 0.],
       [0., 0., 0., 0.]])

```

I would like to get all element indices as follows:

```
indices = [ [0,0],[0,1],[0,2] ... [3,2],[3,3] ]

```