linked_list_queue.py

class Node:
    def __init__(self, data, next=None):
        self.data = data
        self.next = next
 
 
class Queue:
    def __init__(self):
        self.front = None
        self.rear = None
        self.size = 0

 
    def enqueue(self, item):
        self.size += 1
        node = Node(item)
        if self.front is None:
            self.front = node
            self.rear = node
        else:
            self.rear.next = node
            self.rear = node
 
    def dequeue(self):
        self.size -= 1
        if self.front is None:
            raise IndexError('pop from empty queue')
        temp = self.front
        self.front = self.front.next
        if self.front is None:
            self.front = None
        return temp.data
    
    def size(self):
        return self.size
        

queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
queue.enqueue(3)
queue.enqueue(4)
queue.enqueue(5)
for i in range(5):
    print(queue.dequeue())