data = [{'date': datetime.date(2021, 12, 13), 'code': '668561B6DBF1CB7AB'},{'date': datetime.date(2021, 12, 11), 'code': '668561B6DBF1CB7CD'}]
import json
json.dumps(data, sort_keys=True, default=str)
'[{"code": "668561B6DBF1CB7AB", "date": "2021-12-13"},{"code": "668561B6DBF1CB7CD", "date": "2021-12-11"}]'