a = np.array([[1,2],[1,2]]) b = np.repeat(a[:, :, np.newaxis], 3, axis=2) print(b[:, :, 0]) # [[1 2] # [1 2]] print(b[:, :, 1]) # [[1 2] # [1 2]] print(b[:, :, 2]) # [[1 2] # [1 2]]