在AttributeError中使用单链表实现队列

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

class Queue:
    def __init__(self):
        self.head = None
        self.tail = None

    def is_empty(self):
        return self.head is None

    def enqueue(self, data):
        new_node = Node(data)
        if self.is_empty():
            self.head = new_node
            self.tail = new_node
        else:
            self.tail.next = new_node
            self.tail = new_node

    def dequeue(self):
        if self.is_empty():
            raise Exception("Queue is empty")
        data = self.head.data
        self.head = self.head.next
        if self.head is None:
            self.tail = None
        return data

    def peek(self):
        if self.is_empty():
            raise Exception("Queue is empty")
        return self.head.data

queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
queue.enqueue(3)
print(queue.dequeue())  # 输出：1
print(queue.peek())  # 输出：2
print(queue.is_empty())  # 输出：False