TranslationTask

class flash.text.seq2seq.translation.model.TranslationTask(backbone='t5-small', tokenizer_kwargs=None, max_source_length=128, max_target_length=128, padding='max_length', loss_fn=None, optimizer='Adam', lr_scheduler=None, metrics=None, learning_rate=None, num_beams=4, n_gram=4, smooth=True, enable_ort=False)

The TranslationTask is a Task for Seq2Seq text translation. For more details, see Translation.

You can change the backbone to any translation model from HuggingFace/transformers using the backbone argument.

Parameters

• backbone (str) – backbone model to use for the task.

• max_source_length (int) – The maximum length to pad / truncate input sequences to.

• max_target_length (int) – The maximum length to pad / truncate target sequences to.

• padding (Union[str, bool]) – The type of padding to apply. One of: “longest” or True, “max_length”, “do_not_pad” or False.

• loss_fn (Optional[TypeVar(LOSS_FN_TYPE, Callable, Mapping, Sequence, None)]) – Loss function for training.

• optimizer (TypeVar(OPTIMIZER_TYPE, str, Callable, Tuple[str, Dict[str, Any]], None)) – Optimizer to use for training.

• lr_scheduler (Optional[TypeVar(LR_SCHEDULER_TYPE, str, Callable, Tuple[str, Dict[str, Any]], Tuple[str, Dict[str, Any], Dict[str, Any]], None)]) – The LR scheduler to use during training.

• metrics (Optional[TypeVar(METRICS_TYPE, Metric, Mapping, Sequence, None)]) – Metrics to compute for training and evaluation. Defauls to calculating the BLEU metric. Changing this argument currently has no effect.

• learning_rate (Optional[float]) – Learning rate to use for training, defaults to 1e-5

• num_beams (Optional[int]) – Number of beams to use in validation when generating predictions. Defaults to 4

• n_gram (int) – Maximum n_grams to use in metric calculation. Defaults to 4

• smooth (bool) – Apply smoothing in BLEU calculation. Defaults to True

• enable_ort (bool) – Enable Torch ONNX Runtime Optimization: https://onnxruntime.ai/docs/#onnx-runtime-for-training

classmethod available_finetuning_strategies(cls)

Returns a list containing the keys of the available Finetuning Strategies.

Return type

List[str]

classmethod available_lr_schedulers(cls)

Returns a list containing the keys of the available LR schedulers.

Return type

List[str]

classmethod available_optimizers(cls)

Returns a list containing the keys of the available Optimizers.

Return type

List[str]

classmethod available_outputs(cls)

Returns the list of available outputs (that can be used during prediction or serving) for this Task.

Examples

..testsetup:

>>> from flash import Task

>>> print(Task.available_outputs())
['preds', 'raw']

Return type

List[str]

classmethod load_from_checkpoint(cls, checkpoint_path, map_location=None, hparams_file=None, strict=True, **kwargs)

Primary way of loading a model from a checkpoint. When Lightning saves a checkpoint it stores the arguments passed to __init__ in the checkpoint under "hyper_parameters".

Any arguments specified through **kwargs will override args stored in "hyper_parameters".

Parameters

• checkpoint_path (Union[str, Path, IO]) – Path to checkpoint. This can also be a URL, or file-like object

• map_location (Union[device, str, int, Callable[[Union[device, str, int]], Union[device, str, int]], Dict[Union[device, str, int], Union[device, str, int]], None]) – If your checkpoint saved a GPU model and you now load on CPUs or a different number of GPUs, use this to map to the new setup. The behaviour is the same as in torch.load().

• hparams_file (Union[str, Path, None]) –

  Optional path to a .yaml or .csv file with hierarchical structure as in this example:

  drop_prob: 0.2
  dataloader:
      batch_size: 32
  

  You most likely won’t need this since Lightning will always save the hyperparameters to the checkpoint. However, if your checkpoint weights don’t have the hyperparameters saved, use this method to pass in a .yaml file with the hparams you’d like to use. These will be converted into a dict and passed into your LightningModule for use.

  If your model’s hparams argument is Namespace and .yaml file has hierarchical structure, you need to refactor your model to treat hparams as dict.

• strict (bool) – Whether to strictly enforce that the keys in checkpoint_path match the keys returned by this module’s state dict.

• **kwargs – Any extra keyword args needed to init the model. Can also be used to override saved hyperparameter values.

Return type

Self

Returns

LightningModule instance with loaded weights and hyperparameters (if available).

Note

load_from_checkpoint is a class method. You should use your LightningModule class to call it instead of the LightningModule instance.

Example:

# load weights without mapping ...
model = MyLightningModule.load_from_checkpoint('path/to/checkpoint.ckpt')

# or load weights mapping all weights from GPU 1 to GPU 0 ...
map_location = {'cuda:1':'cuda:0'}
model = MyLightningModule.load_from_checkpoint(
    'path/to/checkpoint.ckpt',
    map_location=map_location
)

# or load weights and hyperparameters from separate files.
model = MyLightningModule.load_from_checkpoint(
    'path/to/checkpoint.ckpt',
    hparams_file='/path/to/hparams_file.yaml'
)

# override some of the params with new values
model = MyLightningModule.load_from_checkpoint(
    PATH,
    num_layers=128,
    pretrained_ckpt_path=NEW_PATH,
)

# predict
pretrained_model.eval()
pretrained_model.freeze()
y_hat = pretrained_model(x)