circular_queue.py

"""
Used in alarm.py to create a circular queue of days of the week that
an alarm will repeat on.
https://www.pythoncentral.io/circular-queue/
"""

class CircularQueue:

    #Constructor
    def __init__(self):
        self.queue = list()
        self.head = 0
        self.tail = 0
        self.maxSize = 8

    #Adding elements to the queue
    def enqueue(self,data):
        if self.size() == self.maxSize-1:
            return ("Queue Full!")
        self.queue.append(data)
        self.tail = (self.tail + 1) % self.maxSize
        return True

    #Removing elements from the queue
    def dequeue(self):
        if self.size()==0:
            return ("Queue Empty!") 
        data = self.queue[self.head]
        self.head = (self.head + 1) % self.maxSize
        return data

    #Calculating the size of the queue
    def size(self):
        if self.tail>=self.head:
            return (self.tail-self.head)
        return (self.maxSize - (self.head-self.tail))