new_contents: import argparse
  import glob
  import json
  
  from kvd_utils import download_json, get_session
  
  ext_url_template = 'https://vaalit.yle.fi/content/kv2017/{version}/electorates/{electorate}/municipalities/{municipality}/pollingDistricts/{district}/partyAndCandidateResults.json'
  
  
  def download_ext_data(version):
      sess = get_session()
      for muni_fn in glob.glob('data/{version}/*.json'.format(version=version)):
          with open(muni_fn) as infp:
              muni = json.load(infp)
          name = muni['calculationStatus']['name']['fi']
          perc = float(muni['calculationStatus']['calculationStatusPercent'])
          if perc < 100:
              print('%s: %.2f%% less than 100%% percent, skipping' % (name, perc))
              continue
          for district in muni['pollingDistricts']:
              url = ext_url_template.format(
                  version=version,
                  electorate=muni['calculationStatus']['edid'],
                  municipality=muni['calculationStatus']['muid'],
                  district=district['pdid'],
              )
              output_file = 'ext_data/{version}/{name}/{district}.json'.format(
                  version=version,
                  name=name,
                  district=district['name']['fi'].replace(' ', '_'),
              )
              download_json(sess, url, output_file)
  
  
  if __name__ == '__main__':
      ap = argparse.ArgumentParser()
      ap.add_argument('version', type=int)
      args = ap.parse_args()
      download_ext_data(version=args.version)
  
subject: Add downloader for per-polling-station data