class Bag:
    """ Bag implemented as an array """

    def __init__ ( self ):
        """ Create an empty Bag """
        self.array = [] # an empty array


    def add(self , item ):
        """ Adds an item to the bag """
        self.array += [ item ]

    def contains (self , item ):
        """ Checks if an item is in the bag , returns True or False """
        for i in range (len( self . array )):
            if self.array [i] == item :
                return True
        return False

    def remove (self , item ):
        """ Removes an item from the bag and returns it.
        What to do if its not in there ? """
        index = 0
        for i in range (len( self . array )):
            if self.array [i] == item :
                index = i
                break
        stuff = self.array [ index ]
        self.array = self.array[0: index] + \
                     self.array[index + 1: len(self.array)]
        return stuff

    def is_empty(self):
        """ Check to see if the bag is empty"""
        return len(self.array) == 0

    
    def iterator ( self ):
        """ Returns an iterator for the bag """
        pass