json datetime encoder

json_datetime_encoder.py

class DateTimeEncoder(json.JSONEncoder):

    def _preprocess_date(self, obj):
        if isinstance(obj, (datetime.date, datetime.datetime, datetime.timedelta)):
            return str(obj)
        elif isinstance(obj, dict):
            return {self._preprocess_date(k): self._preprocess_date(v) for k,v in obj.items()}
        elif isinstance(obj, list):
            return [self._preprocess_date(i) for i in obj]
        return obj

    def default(self, obj):
        if isinstance(obj, (datetime.date, datetime.datetime, datetime.timedelta)):
            return str(obj)
        return super().default(obj)

    def iterencode(self, obj):
        return super().iterencode(self._preprocess_date(obj))