enQueue.py

class Queue:
    def __init__(self, capacity):
        self.front = self.size = 0
        self.rear = capacity - 1
        self.Q =[None]*capacity
        self.capacity = capacity

    def isFull(self):
        return self.size == self.capacity

    def isEmpty(self):
        return self.size == 0

    def EnQueue(self, item):
        if self.isFull():
            print('Full')
            return
        self.rear = (self.rear + 1) % (self.capacity)
        self.Q[self.rear] = item
        self.size = self.size + 1
        print('% s enqueued to queue' %str(item))

    def DeQueue(self):
        if self.isEmpty():
            print('Empty')
            return

        print('% s dequeued from queue' % str(self.Q[self.front]))
        self.front = (self.front + 1) % (self.capacity)
        self.size = self.size -1

    def que_front(self):
        if self.isEmpty():
            print('Queue is empty')

        print('Front item is ', self.Q[self.front])

    def que_rear(self):
        if self.isEmpty():
            print('Queue is empty')

        print('Rear item is ', self.Q[self.rear])

#Driver Code

if __name__ == '__main__':
    queue = Queue(30)
    queue.EnQueue(10)
    queue.EnQueue(20)
    queue.EnQueue(30)
    queue.EnQueue(40)
    queue.DeQueue()
    queue.que_front()
    queue.que_rear()