tfx_bsl.public.tfxio.TFXIO

Abstract basic class of all TFXIO API implementations.

Methods

ArrowSchema

@abc.abstractmethod
ArrowSchema() -> pa.Schema

Returns the schema of the RecordBatch produced by self.BeamSource().

May raise an error if the TFMD schema was not provided at construction time.

BeamSource

@abc.abstractmethod
BeamSource(
    batch_size: Optional[int] = None
) -> beam.PTransform

Returns a beam PTransform that produces PCollection[pa.RecordBatch].

May NOT raise an error if the TFMD schema was not provided at construction time.

If a TFMD schema was provided at construction time, all the pa.RecordBatches in the result PCollection must be of the same schema returned by self.ArrowSchema. If a TFMD schema was not provided, the pa.RecordBatches might not be of the same schema (they may contain different numbers of columns).

Args
batch_size if not None, the pa.RecordBatch produced will be of the specified size. Otherwise it's automatically tuned by Beam.

Project

Project(
    tensor_names: List[Text]
) -> 'TFXIO'

Projects the dataset represented by this TFXIO.

A Projected TFXIO:

  • Only columns needed for given tensor_names are guaranteed to be produced by self.BeamSource()
  • self.TensorAdapterConfig() and self.TensorFlowDataset() are trimmed to contain only those tensors.
  • It retains a reference to the very original TFXIO, so its TensorAdapter knows about the specs of the tensors that would be produced by the original TensorAdapter. Also see TensorAdapter.OriginalTensorSpec().

May raise an error if the TFMD schema was not provided at construction time.

Args
tensor_names a set of tensor names.

Returns
A TFXIO instance that is the same as self except that:

  • Only columns needed for given tensor_names are guaranteed to be produced by self.BeamSource()
  • self.TensorAdapterConfig() and self.TensorFlowDataset() are trimmed to contain only those tensors.

RecordBatches

@abc.abstractmethod
RecordBatches(
    options: tfx_bsl.public.tfxio.RecordBatchesOptions
) -> Iterator[pa.RecordBatch]

Returns an iterable of record batches.

This can be used outside of Apache Beam or TensorFlow to access data.

Args
options An options object for iterating over record batches. Look at dataset_options.RecordBatchesOptions for more details.

TensorAdapter

TensorAdapter() -> tfx_bsl.public.tfxio.TensorAdapter

Returns a TensorAdapter that converts pa.RecordBatch to TF inputs.

May raise an error if the TFMD schema was not provided at construction time.

TensorAdapterConfig

TensorAdapterConfig() -> tfx_bsl.public.tfxio.TensorAdapterConfig

Returns the config to initialize a TensorAdapter.

Returns
a TensorAdapterConfig that is the same as what is used to initialize the TensorAdapter returned by self.TensorAdapter().

TensorFlowDataset

@abc.abstractmethod
TensorFlowDataset(
    options: tfx_bsl.public.tfxio.TensorFlowDatasetOptions
) -> tf.data.Dataset

Returns a tf.data.Dataset of TF inputs.

May raise an error if the TFMD schema was not provided at construction time.

Args
options an options object for the tf.data.Dataset. Look at dataset_options.TensorFlowDatasetOptions for more details.

TensorRepresentations

@abc.abstractmethod
TensorRepresentations() -> tfx_bsl.public.tfxio.TensorRepresentations

Returns the TensorRepresentations.

These TensorRepresentations describe the tensors or composite tensors produced by the TensorAdapter created from self.TensorAdapter() or the tf.data.Dataset created from self.TensorFlowDataset().

May raise an error if the TFMD schema was not provided at construction time. May raise an error if the tensor representations are invalid.