使用python deque实现一个队列

from collections import deque

class Queue:
    def __init__(self):
        self.queue = deque()

    def enqueue(self, item):
        self.queue.append(item)

    def dequeue(self):
        if not self.is_empty():
            return self.queue.popleft()

    def is_empty(self):
        return len(self.queue) == 0

    def size(self):
        return len(self.queue)

    def peek(self):
        if not self.is_empty():
            return self.queue[0]

    def __str__(self):
        return str(self.queue)


if __name__ == '__main__':
    queue = Queue()
    queue.enqueue(1)
    queue.enqueue(2)
    queue.enqueue(3)
    print(queue)  # deque([1, 2, 3])
    print(queue.peek())  # 输出 1
    queue.dequeue()
    print(queue.peek())  # 输出 2
    print(queue.dequeue())  # 输出 2
    print(queue.dequeue())  # 输出 3
    print(queue.is_empty())  # 输出 True