[py3] Allowed bytes in get_prep_value for a Geometry

        # from the given string input.

        if isinstance(geom, Geometry):

            pass

        elif isinstance(geom, six.string_types) or hasattr(geom, '__geo_interface__'):

        elif isinstance(geom, (bytes, six.string_types)) or hasattr(geom, '__geo_interface__'):

            try:

                geom = Geometry(geom)

            except GeometryException: