nonzero

nonzero(a)

Return the indices of the elements that are non-zero.

>>> b = np.array([True, False, False, True, False, True])

>>> print(np.nonzero(b))

(array([0, 3, 5]),)

>>> b = np.array([[False, False, False, False],

... [False, False, False, True],

... [False, False, True, True]])

>>>

>>> print(np.nonzero(b))

(array([1, 2, 2]), array([3, 2, 3]))

>>>

row indices

columns indices