code: def export_agg_risk_csv(ekey, dstore):
      
      writer = writers.CsvWriter(fmt=writers.FIVEDIGITS)
      path = '%s.%s' % (sanitize(ekey[0]), ekey[1])
      fname = dstore.export_path(path)
      writer.save(dstore['agg_risk'].value, fname)
      return [fname]
docs: :param ekey: export key, i.e. a pair (datastore key, fmt)
      :param dstore: datastore object