properties.py 文件源码

def _deserialize(cls, data):
        kind = data.get(cls._type_field, None)
        if kind is None:
            return data

        value = data.get("value")
        if kind == "blob":
            return base64.b64decode(value.encode("utf-8"))

        elif kind == "datetime":
            return datetime.fromtimestamp(value, tz.tzutc())

        elif kind == "model":
            return cls._entity_from_dict(value)

        else:
            raise ValueError(f"Invalid kind {kind!r}.")