Prepare an ONS shapefile for BigQuery

ons_shapefile_to_bigquery.py

import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

gdf = gpd.read_file('zip://Regions_December_2022_EN_BUC-shapefile.zip')

# Convert to EPSG:4326 from OSGB36
gdf = gdf.to_crs("EPSG:4326")

def correct_ring_orientation(geometry):
    if isinstance(geometry, Polygon):
        if not geometry.exterior.is_ccw:
            geometry = Polygon(list(geometry.exterior.coords)[::-1], [inner.coords[::-1] if inner.is_ccw else inner.coords[:] for inner in geometry.interiors])
    elif isinstance(geometry, MultiPolygon):
        geometry = MultiPolygon([correct_ring_orientation(poly) for poly in geometry.geoms])
    return geometry

# if you do not do this, MULTIPOLYGONs will not import correctly
gdf['geometry'] = gdf['geometry'].apply(correct_ring_orientation)

# add a wkt column to hold the actual data
gdf['wkt_geometry'] = gdf['geometry'].apply(lambda x: x.wkt)

# write whichever fields you want to a csv, then upload to BQ via Google Cloud Storage
# ensure that you select GEOGRAPHY for the WKT column
gdf[['RGN22CD', 'RGN22NM', 'wkt_geometry']].to_csv('regions.csv', index=False)