Python 带尾节点的双向链表实现

LList1的定义：传送门

from LList1 import *

# 带尾节点的双向链表
class DLNode(LNode):
    def __init__(self, elem, prev_=None, next_=None):
        LNode.__init__(self, elem, next_)
        self.prev = prev_
    
class DLList(LList1):
    def __init__(self) -> None:
        LList1.__init__(self)

    # 前端插入
    def prepend(self, elem_):
        p = DLNode(elem_, None, self.head)
        if self.head is None:
            self.rear = p
        else:
            p.next.pre = p
        self.head = p
    
    # 后端插入
    def append(self, elem_):
        p = DLNode(elem_, self.rear, None)
        if self.head is None:
            self.head = p
        else:
            p.prev.next = p
        self.rear = p
    
    # 前端弹出
    def pop(self):
        p = self.head
        if p is None:
            raise linkedListUnderUnderflow("in pop")
        e = self.head.elem
        if p.next is None:
            self.head = None
        else:
            self.head = self.head.next
            self.head.prev = None
        return e

    # 后端弹出
    def pop_last(self):
        p = self.head
        if p is None:
            raise linkedListUnderUnderflow("in pop_last")
        e = self.head.elem
        self.rear = self.rear.prev
        if self.rear is None:
            self.head = None
        else:
            self.rear.next = None
        return e


    
    # 遍历
    def generate_list(self):
        temp_list = []
        p = self.head
        while p:
            temp_list.append(p.elem)
            p = p.next
        return temp_list
            

if __name__ == '__main__':
    dllist = DLList()
    for i in range(1, 4):
        dllist.append(i)
    print(dllist.generate_list())
    print(dllist.pop())
    print(dllist.generate_list())
    print(dllist.pop_last())
    print(dllist.generate_list())