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prefect.serializers

Serializer implementations for converting objects to bytes and bytes to objects.

All serializers are based on the Serializer class and include a type string that allows them to be referenced without referencing the actual class. For example, you can get often specify the JSONSerializer with the string “json”. Some serializers support additional settings for configuration of serialization. These are stored on the instance so the same settings can be used to load saved objects.

All serializers must implement dumps and loads which convert objects to bytes and bytes to an object respectively.

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Functions

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prefect_json_object_encoder

prefect_json_object_encoder(obj: Any) -> Any

JSONEncoder.default for encoding objects into JSON with extended type support.

Raises a TypeError to fallback on other encoders on failure.

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prefect_json_object_decoder

prefect_json_object_decoder(result: dict[str, Any]) -> Any

JSONDecoder.object_hook for decoding objects from JSON when previously encoded with prefect_json_object_encoder

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Classes

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Serializer

A serializer that can encode objects of type ‘D’ into bytes.

Methods:

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dumps

dumps(self, obj: D) -> bytes

Encode the object into a blob of bytes.

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loads

loads(self, blob: bytes) -> D

Decode the blob of bytes into an object.

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PickleSerializer

Serializes objects using the pickle protocol.

• Uses cloudpickle by default. See picklelib for using alternative libraries.
• Stores the version of the pickle library to check for compatibility during deserialization.
• Wraps pickles in base64 for safe transmission.

Methods:

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check_picklelib

check_picklelib(cls, value: str) -> str

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dumps

dumps(self, obj: D) -> bytes

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loads

loads(self, blob: bytes) -> D

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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.

Methods:

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dumps_kwargs_cannot_contain_default

dumps_kwargs_cannot_contain_default(cls, value: dict[str, Any]) -> dict[str, Any]

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loads_kwargs_cannot_contain_object_hook

loads_kwargs_cannot_contain_object_hook(cls, value: dict[str, Any]) -> dict[str, Any]

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dumps

dumps(self, obj: D) -> bytes

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loads

loads(self, blob: bytes) -> D

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CompressedSerializer

Wraps another serializer, compressing its output. Uses lzma by default. See compressionlib for using alternative libraries.

Methods:

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validate_serializer

validate_serializer(cls, value: Union[str, Serializer[D]]) -> Serializer[D]

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check_compressionlib

check_compressionlib(cls, value: str) -> str

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dumps

dumps(self, obj: D) -> bytes

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loads

loads(self, blob: bytes) -> D

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CompressedPickleSerializer

A compressed serializer preconfigured to use the pickle serializer.

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CompressedJSONSerializer

A compressed serializer preconfigured to use the json serializer.