python implements queue

Implementation of the queue

Like stacks, queues can also be implemented using sequential or linked lists.

operate

• Queue() creates an empty queue
• enqueue(item) adds an item element to the queue
• dequeue() removes an element from the head of the queue
• is_empty() determines whether a queue is empty
• size() returns the size of the queue

class Queue(object):
    '''Queue, first in first out'''
    def __init__(self):
        self.__list = []

    def enqueue(self, item):
        '''Add elements from one end'''
        self.__list.append(item)

    def dequeue(self):
        '''Add element from the other end'''
        return self.__list.pop(0)

    def is_empty(self):
        '''Determine whether it is empty'''
        return self.__list == []

    def length(self):
        '''Get the length of the queue'''
        return len(self.__list)


if __name__ == '__main__':
    q = Queue()
    q.enqueue(1)
    q.enqueue(2)
    q.enqueue(3)
    q.enqueue(4)

    print(q.dequeue())
    print(q.dequeue())
    print(q.dequeue())

    print(q.length())
    print(q.is_empty())

operation result:

/home/longhui/Desktop/Data Structures and Algorithms/venv/bin/python /home/longhui/Desktop/Data Structures and Algorithms/venv/MyCode/5_queue/my_queue.py
1
2
3
1
False

Process finished with exit code 0