ObserverCode

class NoView(Exception):
    """The view does not exist."""
    pass

class NoController(Exception):
    """The controller does not exist."""
    pass

class Observer:
    def __init__(self, aView, aController):
        """Construct the instance."""
        self.__dict = {}
        self.__dict['view'] = aView
        self.__dict['controller'] = aController
        return

    def __del__(self):
        """Destroy the instance."""
        self.finished()
        return

    def finished(self):
        """Manually break the loops."""
        for item in self.__dict.values():
            if item:
                item.finished()
        self.__dict = {}
        self.__dict['view'] = None
        self.__dict['controller'] = None
        return

    def getView(self):
        """Return the view."""
        result = None
        if self.__dict['view']:
            result = self.__dict['view']
        else:
            raise NoView
        return result

    def getController(self):
        """Return the controller."""
        result = None
        if self.__dict['controller']:
            result = self.__dict['controller']
        else:
            raise NoController
        return result

    def __getitem__(self, key):
        """Private helper."""
        return self.__dict[key]