def test_find_next(): """ This should return a generator yielding the nearest larger element in list2 for each element in list1 (or None if none exists after the previous element yielded from list2). """ list1 = [1, 2, 3, 4, 5, 6, 7, 8, 9] list2 = [0, 2, 3, 5, 0, 0, 5, 9, 10, 15] assert list(util.find_next(list1, list2, None)) == [(1, 2), (2, 3), (3, 5), (4, 5), (5, 9), (6, 10), (7, 15), (8, None), (9, None)]