def equal_lists(left, right):
    """
    Compares two lists and returs True if they contain the same elements, but
    doesn't require that they have the same order.
    """
    right = list(right)
    if len(left) != len(right):
        return False
    for item in left:
        if item in right:
            del right[right.index(item)]
        else:
            return False
    return True