- class flytekit.types.structured.StructuredDatasetEncoder(python_type, protocol=None, supported_format=None)[source]#
Extend this abstract class, implement the encode function, and register your concrete class with the StructuredDatasetTransformerEngine class in order for the core flytekit type engine to handle dataframe libraries. This is the encoding interface, meaning it is used when there is a Python value that the flytekit type engine is trying to convert into a Flyte Literal. For the other way, see the StructuredDatasetEncoder
python_type (Type[T]) – The dataframe class in question that you want to register this encoder with
protocol (Optional[str]) – A prefix representing the storage driver (e.g. ‘s3, ‘gs’, ‘bq’, etc.). You can use either “s3” or “s3://”. They are the same since the “://” will just be stripped by the constructor. If None, this encoder will be registered with all protocols that flytekit’s data persistence layer is capable of handling.
supported_format (Optional[str]) – Arbitrary string representing the format. If not supplied then an empty string will be used. An empty string implies that the encoder works with any format. If the format being asked for does not exist, the transformer enginer will look for the “” endcoder instead and write a warning.
- abstract encode(ctx, structured_dataset, structured_dataset_type)[source]#
Even if the user code returns a plain dataframe instance, the dataset transformer engine will wrap the incoming dataframe with defaults set for that dataframe type. This simplifies this function’s interface as a lot of data that could be specified by the user using the # TODO: Do we need to add a flag to indicate if it was wrapped by the transformer or by the user?
structured_dataset (flytekit.types.structured.structured_dataset.StructuredDataset) – This is a StructuredDataset wrapper object. See more info above.
structured_dataset_type (flytekit.models.types.StructuredDatasetType) – This the StructuredDatasetType, as found in the LiteralType of the interface of the task that invoked this encoding call. It is passed along to encoders so that authors of encoders can include it in the returned literals.StructuredDataset. See the IDL for more information on why this literal in particular carries the type information along with it. If the encoder doesn’t supply it, it will also be filled in after the encoder runs by the transformer engine.
This function should return a StructuredDataset literal object. Do not confuse this with the StructuredDataset wrapper class used as input to this function - that is the user facing Python class. This function needs to return the IDL StructuredDataset.
- Return type