import sys sys.path.insert(0, '.') from singly_linked_list import SinglyLinkedList sll = SinglyLinkedList() sll.insert_at_index(0, 9999) sll.insert_at_start(1) sll.insert_before_item(1, 111) sll.insert_at_start(2) sll.insert_at_index(2, 5) sll.insert_at_index(5, 5) sll.print_singley_linked_list() sll.swap_node_pair()