prefect.serializers

Data serializer implementations

These serializers are registered for use with DataDocument types

JSONSerializer

Serializes data to JSON.

Input types must be compatible with the stdlib json library.

Wraps the json library to serialize to UTF-8 bytes instead of string types.

Source code in prefect/serializers.py

class JSONSerializer:
    """
    Serializes data to JSON.

    Input types must be compatible with the stdlib json library.

    Wraps the `json` library to serialize to UTF-8 bytes instead of string types.
    """

    @staticmethod
    def dumps(data: Any) -> bytes:
        return json.dumps(data).encode()

    @staticmethod
    def loads(blob: bytes) -> Any:
        return json.loads(blob.decode())

PackageManifestSerializer

Serializes a package manifest.

Source code in prefect/serializers.py

class PackageManifestSerializer:
    """
    Serializes a package manifest.
    """

    @staticmethod
    def dumps(data: "PackageManifest") -> bytes:
        return data.json().encode()

    @staticmethod
    def loads(blob: bytes) -> "PackageManifest":
        from prefect.packaging.base import PackageManifest

        return PackageManifest.parse_raw(blob)

PickleSerializer

Serializes arbitrary objects using the pickle protocol.

Wraps cloudpickle to encode bytes in base64 for safe transmission.

Source code in prefect/serializers.py

class PickleSerializer:
    """
    Serializes arbitrary objects using the pickle protocol.

    Wraps `cloudpickle` to encode bytes in base64 for safe transmission.
    """

    @staticmethod
    def dumps(data: Any) -> bytes:
        data_bytes = cloudpickle.dumps(data)

        return base64.encodebytes(data_bytes)

    @staticmethod
    def loads(blob: bytes) -> Any:
        return cloudpickle.loads(base64.decodebytes(blob))
        # TODO: Consider adding python version data to pickle payloads to raise
        #       more helpful errors for users.
        #       A TypeError("expected bytes-like object, not int") will be raised if
        #       a document is deserialized by Python 3.7 and serialized by 3.8+

ResultSerializer

Serializes a result object

Source code in prefect/serializers.py

class ResultSerializer:
    """
    Serializes a result object
    """

    @staticmethod
    def dumps(data: "_Result") -> bytes:
        return data.json().encode()

    @staticmethod
    def loads(blob: bytes) -> "_Result":
        from prefect.results import _Result

        return _Result.parse_raw(blob)