def insert_at_tail(self, data): node = Node(data) curr = self.head while curr.next: curr = curr.next curr.next = node node.prev = curr
def insert_after(self, locdata, data): node = Node(data) curr = self.head while curr.data != locdata and curr.next: curr = curr.next node.prev = curr node.next = curr.next node.next.prev = node curr.next = node
def insert_at_pos(self, pos, data): node = Node(data) curr = self.head count = 1 while count != pos and curr.next: curr = curr.next count += 1 node.prev = curr node.next = curr.next node.next.prev = node curr.next = node