code: def get_grid_district_polygon(config, subst_id=None, projection=4326):
      
  
      # make DB session
      conn = connection(section=config['db_connection']['section'])
      Session = sessionmaker(bind=conn)
      session = Session()
  
      # get polygon from versioned schema
      if config['data_source']['oedb_data_source'] == 'versioned':
  
          version = config['versioned']['version']
          query = session.query(EgoDpMvGriddistrict.subst_id,
                                EgoDpMvGriddistrict.geom)
          Regions = [(subst_id, shape.to_shape(geom)) for subst_id, geom in
                     query.filter(EgoDpMvGriddistrict.version == version,
                                  EgoDpMvGriddistrict.subst_id == subst_id).all()
                     ]
  
      # get polygon from model_draft
      else:
          query = session.query(EgoGridMvGriddistrict.subst_id,
                                EgoGridMvGriddistrict.geom)
          Regions = [(subst_id, shape.to_shape(geom)) for subst_id, geom in
                     query.filter(EgoGridMvGriddistrict.subst_id.in_(
                         subst_id)).all()]
  
      crs = {'init': 'epsg:3035'}
      region = gpd.GeoDataFrame(
          Regions, columns=['subst_id', 'geometry'], crs=crs)
      region = region.to_crs(epsg=projection)
  
      return region
docs: Get MV grid district polygon from oedb for plotting.