q4
def pop_random_element(self, the_list):
        """This method picks a random element from a list, removes that
        element from the list and returns the element.

        Note:  the pop() function might be useful here
        """

        popped = the_list.pop(random.randint(0,len(the_list)-1))
        return(popped)
--------------------------------------------------
q5
def append_unique(self, src, dst):
        """This method appends the elements of the src list to the dst list,
        but only if they are not already in the dst list.  In other words, the
        dst list is increased by adding new elements from the src list.
        """
        for i in src:
            if i not in dst:
                dst.append(i)

        pass