Pipeline

CuratedTransformer

classv3.7
String name:curated_transformer
Pipeline component for multi-task learning with Curated Transformer models

This pipeline component lets you use a curated set of transformer models in your pipeline. spaCy Curated Transformers currently supports the following model types:

  • ALBERT
  • BERT
  • CamemBERT
  • RoBERTa
  • XLM-RoBERT

If you want to use another type of model, use spacy-transformers, which allows you to use all Hugging Face transformer models with spaCy.

You will usually connect downstream components to a shared Curated Transformer pipe using one of the Curated Transformer listener layers. This works similarly to spaCy’s Tok2Vec, and the Tok2VecListener sublayer. The component assigns the output of the transformer to the Doc’s extension attributes. To access the values, you can use the custom Doc._.trf_data attribute.

For more details, see the usage documentation.

Assigned Attributes

The component sets the following custom extension attribute:

LocationValue
Doc._.trf_dataCurated Transformer outputs for the Doc object. DocTransformerOutput

Config and Implementation

The default config is defined by the pipeline component factory and describes how the component should be configured. You can override its settings via the config argument on nlp.add_pipe or in your config.cfg for training. See the model architectures documentation for details on the curated transformer architectures and their arguments and hyperparameters.

SettingDescription
modelThe Thinc Model wrapping the transformer. Defaults to XlmrTransformer. Model
frozenIf True, the model’s weights are frozen and no backpropagation is performed. bool
all_layer_outputsIf True, the model returns the outputs of all the layers. Otherwise, only the output of the last layer is returned. This must be set to True if any of the pipe’s downstream listeners require the outputs of all transformer layers. bool
explosion/spacy-curated-transformers/main/spacy_curated_transformers/pipeline/transformer.py

CuratedTransformer.__init__ method

Construct a CuratedTransformer component. One or more subsequent spaCy components can use the transformer outputs as features in its model, with gradients backpropagated to the single shared weights. The activations from the transformer are saved in the Doc._.trf_data extension attribute. You can also provide a callback to set additional annotations. In your application, you would normally use a shortcut for this and instantiate the component using its string name and nlp.add_pipe.

NameDescription
vocabThe shared vocabulary. Vocab
modelOne of the supported pre-trained transformer models. Model
keyword-only
nameThe component instance name. str
frozenIf True, the model’s weights are frozen and no backpropagation is performed. bool
all_layer_outputsIf True, the model returns the outputs of all the layers. Otherwise, only the output of the last layer is returned. This must be set to True if any of the pipe’s downstream listeners require the outputs of all transformer layers. bool

CuratedTransformer.__call__ method

Apply the pipe to one document. The document is modified in place, and returned. This usually happens under the hood when the nlp object is called on a text and all pipeline components are applied to the Doc in order. Both __call__ and pipe delegate to the predict and set_annotations methods.

NameDescription
docThe document to process. Doc

CuratedTransformer.pipe method

Apply the pipe to a stream of documents. This usually happens under the hood when the nlp object is called on a text and all pipeline components are applied to the Doc in order. Both __call__ and pipe delegate to the predict and set_annotations methods.

NameDescription
streamA stream of documents. Iterable[Doc]
keyword-only
batch_sizeThe number of documents to buffer. Defaults to 128. int

CuratedTransformer.initialize method

Initialize the component for training and return an Optimizer. get_examples should be a function that returns an iterable of Example objects. At least one example should be supplied. The data examples are used to initialize the model of the component and can either be the full training data or a representative sample. Initialization includes validating the network, inferring missing shapes and setting up the label scheme based on the data. This method is typically called by Language.initialize.

NameDescription
get_examplesFunction that returns gold-standard annotations in the form of Example objects. Must contain at least one Example. Callable[[], Iterable[Example]]
keyword-only
nlpThe current nlp object. Defaults to None. Optional[Language]
encoder_loaderInitialization callback for the transformer model. Optional[Callable]
piece_loaderInitialization callback for the input piece encoder. Optional[Callable]

CuratedTransformer.predict method

Apply the component’s model to a batch of Doc objects without modifying them.

NameDescription
docsThe documents to predict. Iterable[Doc]

CuratedTransformer.set_annotations method

Assign the extracted features to the Doc objects. By default, the DocTransformerOutput object is written to the Doc._.trf_data attribute. Your set_extra_annotations callback is then called, if provided.

NameDescription
docsThe documents to modify. Iterable[Doc]
scoresThe scores to set, produced by CuratedTransformer.predict.

CuratedTransformer.update method

Prepare for an update to the transformer.

Like the Tok2Vec component, the CuratedTransformer component is unusual in that it does not receive “gold standard” annotations to calculate a weight update. The optimal output of the transformer data is unknown; it’s a hidden layer inside the network that is updated by backpropagating from output layers.

The CuratedTransformer component therefore does not perform a weight update during its own update method. Instead, it runs its transformer model and communicates the output and the backpropagation callback to any downstream components that have been connected to it via the transformer listener sublayer. If there are multiple listeners, the last layer will actually backprop to the transformer and call the optimizer, while the others simply increment the gradients.

NameDescription
examplesA batch of Example objects. Only the Example.predicted Doc object is used, the reference Doc is ignored. Iterable[Example]
keyword-only
dropThe dropout rate. float
sgdAn optimizer. Will be created via create_optimizer if not set. Optional[Optimizer]
lossesOptional record of the loss during training. Updated using the component name as the key. Optional[Dict[str, float]]

CuratedTransformer.create_optimizer method

Create an optimizer for the pipeline component.

NameDescription

CuratedTransformer.use_params methodcontextmanager

Modify the pipe’s model to use the given parameter values. At the end of the context, the original parameters are restored.

NameDescription
paramsThe parameter values to use in the model. dict

CuratedTransformer.to_disk method

Serialize the pipe to disk.

NameDescription
pathA path to a directory, which will be created if it doesn’t exist. Paths may be either strings or Path-like objects. Union[str,Path]
keyword-only
excludeString names of serialization fields to exclude. Iterable[str]

CuratedTransformer.from_disk method

Load the pipe from disk. Modifies the object in place and returns it.

NameDescription
pathA path to a directory. Paths may be either strings or Path-like objects. Union[str,Path]
keyword-only
excludeString names of serialization fields to exclude. Iterable[str]

CuratedTransformer.to_bytes method

Serialize the pipe to a bytestring.

NameDescription
keyword-only
excludeString names of serialization fields to exclude. Iterable[str]

CuratedTransformer.from_bytes method

Load the pipe from a bytestring. Modifies the object in place and returns it.

NameDescription
bytes_dataThe data to load from. bytes
keyword-only
excludeString names of serialization fields to exclude. Iterable[str]

Serialization Fields

During serialization, spaCy will export several data fields used to restore different aspects of the object. If needed, you can exclude them from serialization by passing in the string names via the exclude argument.

NameDescription
vocabThe shared Vocab.
cfgThe config file. You usually don’t want to exclude this.
modelThe binary model data. You usually don’t want to exclude this.

DocTransformerOutput dataclass

Curated Transformer outputs for one Doc object. Stores the dense representations generated by the transformer for each piece identifier. Piece identifiers are grouped by token. Instances of this class are typically assigned to the Doc._.trf_data extension attribute.

NameDescription
all_outputsList of Ragged tensors that correspends to outputs of the different transformer layers. Each tensor element corresponds to a piece identifier’s representation. List[Ragged]
last_layer_onlyIf only the last transformer layer’s outputs are preserved. bool

DocTransformerOutput.embedding_layer property

Return the output of the transformer’s embedding layer or None if last_layer_only is True.

NameDescription

DocTransformerOutput.last_hidden_layer_state property

Return the output of the transformer’s last hidden layer.

NameDescription

DocTransformerOutput.all_hidden_layer_states property

Return the outputs of all transformer layers (excluding the embedding layer).

NameDescription

DocTransformerOutput.num_outputs property

Return the number of layer outputs stored in the DocTransformerOutput instance (including the embedding layer).

NameDescription

Span Getters

Span getters are functions that take a batch of Doc objects and return a lists of Span objects for each doc to be processed by the transformer. This is used to manage long documents by cutting them into smaller sequences before running the transformer. The spans are allowed to overlap, and you can also omit sections of the Doc if they are not relevant. Span getters can be referenced in the [components.transformer.model.with_spans] block of the config to customize the sequences processed by the transformer.

NameDescription
docsA batch of Doc objects. Iterable[Doc]

WithStridedSpans.v1 registered function

Create a span getter for strided spans. If you set the window and stride to the same value, the spans will cover each token once. Setting stride lower than window will allow for an overlap, so that some tokens are counted twice. This can be desirable, because it allows all tokens to have both a left and right context.

NameDescription
windowThe window size. int
strideThe stride size. int

Model Loaders

Curated Transformer models are constructed with default hyperparameters and randomized weights when the pipeline is created. To load the weights of an existing pre-trained model into the pipeline, one of the following loader callbacks can be used. The pre-trained model must have the same hyperparameters as the model used by the pipeline.

HFTransformerEncoderLoader.v1 registered_function

Construct a callback that initializes a supported transformer model with weights from a corresponding HuggingFace model.

NameDescription
nameName of the HuggingFace model. str
revisionName of the model revision/branch. str

PyTorchCheckpointLoader.v1 registered_function

Construct a callback that initializes a supported transformer model with weights from a PyTorch checkpoint.

NameDescription
pathPath to the PyTorch checkpoint. Path

Tokenizer Loaders

Curated Transformer models must be paired with a matching tokenizer (piece encoder) model in a spaCy pipeline. As with the transformer models, tokenizers are constructed with an empty vocabulary during pipeline creation - They need to be initialized with an appropriate loader before use in training/inference.

ByteBPELoader.v1 registered_function

Construct a callback that initializes a Byte-BPE piece encoder model.

NameDescription
vocab_pathPath to the vocabulary file. Path
merges_pathPath to the merges file. Path

CharEncoderLoader.v1 registered_function

Construct a callback that initializes a character piece encoder model.

NameDescription
pathPath to the serialized character model. Path
bos_piecePiece used as a beginning-of-sentence token. Defaults to "[BOS]". str
eos_piecePiece used as a end-of-sentence token. Defaults to "[EOS]". str
unk_piecePiece used as a stand-in for unknown tokens. Defaults to "[UNK]". str
normalizeUnicode normalization form to use. Defaults to "NFKC". str

HFPieceEncoderLoader.v1 registered_function

Construct a callback that initializes a HuggingFace piece encoder model. Used in conjunction with the HuggingFace model loader.

NameDescription
nameName of the HuggingFace model. str
revisionName of the model revision/branch. str

SentencepieceLoader.v1 registered_function

Construct a callback that initializes a SentencePiece piece encoder model.

NameDescription
pathPath to the serialized SentencePiece model. Path

WordpieceLoader.v1 registered_function

Construct a callback that initializes a WordPiece piece encoder model.

NameDescription
pathPath to the serialized WordPiece model. Path

Callbacks

gradual_transformer_unfreezing.v1 registered_function

Construct a callback that can be used to gradually unfreeze the weights of one or more Transformer components during training. This can be used to prevent catastrophic forgetting during fine-tuning.

NameDescription
target_pipesA dictionary whose keys and values correspond to the names of Transformer components and the training step at which they should be unfrozen respectively. Dict[str, int]