尝试使用Node类和链接列表类删除列表中的最后一个元素

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

    def append(self, data):
        new_node = Node(data)
        if self.head is None:
            self.head = new_node
        else:
            current = self.head
            while current.next:
                current = current.next
            current.next = new_node

    def delete_last(self):
        if self.head is None:
            return
        elif self.head.next is None:
            self.head = None
        else:
            current = self.head
            while current.next.next:
                current = current.next
            current.next = None

    def display(self):
        elements = []
        current = self.head
        while current:
            elements.append(current.data)
            current = current.next
        return elements

my_list = LinkedList()
my_list.append(1)
my_list.append(2)
my_list.append(3)
my_list.append(4)

my_list.delete_last()

print(my_list.display())  # 输出 [1, 2, 3]