gistfile1.py

    @classmethod
    def find(cls, session, name_or_id):
        """Find a resource by its name or id.

        :param session: The session to use for making this request.
        :type session: :class:`~openstack.session.Session`
        :param name_or_id: The resource to find. This is a value which
                           will tried first as the ``id_attribute``
                           of the Resource, and additionally as the
                           ``name_attribute``.

        :return: The :class:`Resource` object matching the given name or id
                 or None if nothing matches.
        """
        try:
            res = cls({cls.id_attribute: name_or_id})
            res.get(session)
            return res
        except exceptions.HttpException:
            pass

        try:
            res = cls.list(session, limit=1, marker=name_or_id,
                           paginated=False)
            return next(res)
        except (exceptions.HttpException, StopIteration):
            pass

        return