code: def fetch_deputies(data_dir):
      
      deputies = DeputiesDataset()
      df = deputies.fetch()
      save_to_csv(df, data_dir, "deputies")
  
      holders = df.condition == 'Holder'
      substitutes = df.condition == 'Substitute'
      log.info("Total deputies:", len(df))
      log.info("Holder deputies:", len(df[holders]))
      log.info("Substitute deputies:", len(df[substitutes]))
      return df
docs: :param data_dir: (str) directory in which the output file will be saved