import numpy as np
arr = np.array([[[1,2,3,4],[1,3,4,6]],
                [[1,3,3,4],[3,3,6,4]],
                [[1,2,3,4],[1,3,4,6]]])

unique_arr = [[[1,2,3,4],[1,3,4,6]],
              [[1,3,3,4],[3,3,6,4]]]

import numpy as np
arr1 = np.array([[[1,2,3,4],[1,3,4,6]],
                [[1,3,3,4],[3,3,6,4]],
                [[5,2,9,4],[1,3,4,6]]])

arr2 = np.array([[5,2,9,4],[1,3,4,6]]],
                 [[6,3,7,4],[3,3,6,4]],
                 [[4,2,3,4],[1,3,4,6]]])

diff_arr = [[[1,2,3,4],[1,3,4,6]],
              [[1,3,3,4],[3,3,6,4]]]