Intro to Data Structure Queue

# Queue data structure - First in first out (FIFO)

"""
The queue data structure also means the same where the data elements are arranged in a queue.
The uniqueness of queue lies in the way items are added and removed.
The items are allowed at end but removed form the other end. So it is a First-in-First out method.

We can add elements by using insert() and remove elements by using pop method

"""

class Queue:
    def __init__(self):
        self.queue = list()

    def add(self,data):
        if data not in self.queue:
            self.queue.insert(0,data)
            return True
        return False

    def showelements(self):
        for elm in self.queue:
            print(elm)

    def remove(self):
        if len(self.queue)>0:
            return self.queue.pop()
        return "No element found"

theQueue = Queue()

theQueue.add('mon')
theQueue.add('tue')
theQueue.add('wed')

theQueue.remove()
theQueue.showelements()