How to use the geoalchemy2.functions.ST_DWithin function in GeoAlchemy2

geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0))

        elif 'bbox' in geometry and 'geom' in geometry:
            geom_bbox = geometry['bbox'].wkt
            geom = geometry['geom'].wkt
            filters.append(  # in bbox
                geo_func.ST_DWithin(
                    geo_func.ST_Intersection(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']),
                                             type_coerce(geom_bbox, Geography)), Pois.geom, 0))

        elif 'bbox' not in geometry and 'geom' in geometry:

            geom = geometry['geom'].wkt

            filters.append(  # buffer around geom
                geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0)
            )

        return filters, geom

def generate_geom_filters(geometry, Pois):
        filters, geom = [], None

        if 'bbox' in geometry and 'geom' not in geometry:
            geom = geometry['bbox'].wkt
            filters.append(
                geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0))

        elif 'bbox' in geometry and 'geom' in geometry:
            geom_bbox = geometry['bbox'].wkt
            geom = geometry['geom'].wkt
            filters.append(  # in bbox
                geo_func.ST_DWithin(
                    geo_func.ST_Intersection(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']),
                                             type_coerce(geom_bbox, Geography)), Pois.geom, 0))

        elif 'bbox' not in geometry and 'geom' in geometry:

            geom = geometry['geom'].wkt

            filters.append(  # buffer around geom
                geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0)
            )

def refine_with_user_area(query):
    """Takes a query and refines it with a spatial constraint
    based on user setting"""
    if 'lon' and 'lat' and 'radius' in session:
        return query.filter(ST_DWithin(
            cast(Task.location, Geography),
            cast(from_shape(Point(session["lon"], session["lat"])), Geography),
            session["radius"]))
    else:
        return query

def generate_geom_filters(geometry, Pois):
        filters, geom = [], None

        if 'bbox' in geometry and 'geom' not in geometry:
            geom = geometry['bbox'].wkt
            filters.append(
                geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0))

        elif 'bbox' in geometry and 'geom' in geometry:
            geom_bbox = geometry['bbox'].wkt
            geom = geometry['geom'].wkt
            filters.append(  # in bbox
                geo_func.ST_DWithin(
                    geo_func.ST_Intersection(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']),
                                             type_coerce(geom_bbox, Geography)), Pois.geom, 0))

        elif 'bbox' not in geometry and 'geom' in geometry:

            geom = geometry['geom'].wkt

            filters.append(  # buffer around geom
                geo_func.ST_DWithin(geo_func.ST_Buffer(type_coerce(geom, Geography), geometry['buffer']), Pois.geom, 0)
            )

        return filters, geom