espnet3.components.dataset.DatasetWithTransform

source

class espnet3.components.dataset.DatasetWithTransform(dataset, transform, preprocessor, use_espnet_preprocessor=False)

Bases: object

Lightweight wrapper for applying a transform function to dataset items.

This class wraps a dataset and applies a user-defined transform followed by a preprocessor function. It also supports ESPnet-style UID handling, where the preprocessor receives both a UID and the sample.

• Parameters:
  • dataset (Any) – A dataset implementing __getitem__ and __len__.
  • transform (Callable) – A function applied to each sample before preprocessor.
  • preprocessor (Callable) – A function applied after the transform. If use_espnet_preprocessor is True, it must accept (uid, sample) as arguments. Otherwise, it must accept a single sample.
  • use_espnet_preprocessor (bool) – Whether to include the UID when calling the preprocessor. Required for ESPnet’s AbsPreprocessor compatibility.

Example

>>> def transform(sample):
...     return {
...         "text": sample["text"].upper()
...     }
>>>
>>> def preprocessor(uid, sample):
...     return {
...         "text": f"[uid={uid}] " + sample["text"]
...     }
>>>
>>> wrapped = DatasetWithTransform(
...     my_dataset,
...     transform,
...     preprocessor,
...     use_espnet_preprocessor=True
... )
>>> uid_sample = wrapped[0]
>>> print(uid_sample["text"])
[uid=0] HELLO

• Raises:
  • TypeError – If preprocessor is not callable.
  • TypeError – If transform is not callable.