Queue 是資料集合，僅允許在列表的一端插入，另一端刪除

性質：先進先出

程式碼實現

class Queue:
    def __init__(self, size=100):
        self.queue = [0 for _ in range(size)]
        self.size = size
        self.rear = 0  # 隊尾指標
        self.front = 0  # 隊首指標

    def push(self, element):
        if not self.is_filled(
 
):
            self.rear = (self.rear + 1) % self.size
            self.queue[self.rear] = element
        else:
            raise IndexError("Queue is filled.")

    def pop(self):
        if not self.is_empty():
            self.front = (self.front + 1) % self.size
            return self.queue[self.
 
front]
        else:
            raise IndexError("Queue is empty.")

    # 判斷隊空
    def is_empty(self):
        return self.rear == self.front

    # 判斷隊滿
    def is_filled(self):
        return (self.rear + 1) % self.size == self.front


q = Queue(5)
for i in range(4):
    q.push(i)
print(q.pop())
 

q.push(4)

佇列內建模組

from collections import deque

# q = deque([1,2,3,4,5], 5)
# q.append(6) # 隊尾進隊
# print(q.popleft()) # 隊首出隊

# 用於雙向佇列
# q.appendleft(1) # 隊首進隊
# q.pop() # 隊尾出隊

def tail(n):
    with open('test.txt', 'r') as f:
        q = deque(f, n)
        return q

for line in tail(5):
    print(line, end='')