cleanup.py

 def cleanup_db_tables(self):
    """Cleanup RDS data tables on a periodic basis."""
    def clean_celery_taskmeta():
      num_days = os.environ.get('KEEP_DB_META_NUM_DAYS', '30')
      self.cleanup_tables('celery_taskmeta', 'date_done', num_days)

    def clean_worker_results()
      num_days = os.environ.get('KEEP_WORKER_RESULT_NUM_DAYS', '30')
      self.cleanup_tables('worker_results', 'ended_at', num_days)

    ...
    cleanup_tables = [clean_celery_taskmeta, clean_worker_results, ]

    for clean in cleanup_db_tables:
      try:
        clean()
      except Exception as e:
        logger.error("cleanup failed for %s with exception %r", clean.__name__, e)