# 6.S189 Sample Solutions - Exercise 8.3
# queue_sol.py

# **********  Exercise 8.3 **********

class Queue(object):

    def __init__(self):
        "Initializes 1 attribute: a list to keep track of the queue's elements"
        self.qlist = []

    def insert(self, element):
        "Adds an element to the attribute list using append"
        self.qlist.append(element)

    def remove(self):
        "Removess an element from the attribute list"
        # Check if the list is empty; if so then display a message
        if self.qlist == []:
            print 'The queue is empty'
        else:
            # Otherwise we want to remove the first element from the list
            # and return that to the user.
            element = self.qlist[0]
            self.qlist.remove(element)
            return element
            # Can also do this in 1 line:
            # return self.qlist.pop(0)
            

# Test for Exercise 8.3
queue = Queue()
queue.insert(5)
queue.insert(6.5)
queue.insert('Bear')
print queue.remove() == 5
print queue.remove() == 6.5
print queue.remove() == 'Bear'
queue.remove()