def dict_value_property(dictionary, key):
    """Create a read-only property

    Args:
        dictionary (dict): Dictionary in object..
        key (str): Case-sensitive dictionary key.

    Returns:
        A property instance that can be assigned to a class variable.
    """

    def fget(self):
        dictionary_obj = getattr(self, dictionary)
        try:
            return dictionary_obj[key] or None
        except KeyError:
            return None

    return property(fget)