def test_length(self): ll = DoublyLinkedList() assert ll.length() == 0 # append and prepend operations increase length ll.append('B') assert ll.length() == 1 ll.prepend('A') assert ll.length() == 2 ll.append('C') assert ll.length() == 3 # delete operations decrease length # assert(ll) == DoublyLinkedList(['A', 'B', 'C']) assert(ll.head.data) == 'A' assert(ll.head.prev) == None assert(ll.head.next.prev.data) == 'A' assert(ll.tail.data) == 'C' assert(ll.tail.prev.data) == 'B' assert(ll.tail.next) == None ll.delete('B') assert ll.length() == 2 ll.delete('C') assert ll.length() == 1 ll.delete('A') assert ll.length() == 0
def test_length(self): dll = DoublyLinkedList() assert dll.length() == 0 # append and prepend operations increase length dll.append('B') assert dll.length() == 1 dll.prepend('A') assert dll.length() == 2 dll.append('C') assert dll.length() == 3 # delete operations decrease length dll.delete('B') assert dll.length() == 2 dll.delete('C') assert dll.length() == 1 dll.delete('A') assert dll.length() == 0