transformers/docs/source/en/internal/generation_utils.md

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# Utilities for Generation

This page lists all the utility functions used by [`~generation.GenerationMixin.generate`].

## Generate Outputs

The output of [`~generation.GenerationMixin.generate`] is an instance of a subclass of
[`~utils.ModelOutput`]. This output is a data structure containing all the information returned
by [`~generation.GenerationMixin.generate`], but that can also be used as tuple or dictionary.

Here's an example:

```python
from transformers import GPT2Tokenizer, GPT2LMHeadModel

tokenizer = GPT2Tokenizer.from_pretrained("openai-community/gpt2")
model = GPT2LMHeadModel.from_pretrained("openai-community/gpt2")

inputs = tokenizer("Hello, my dog is cute and ", return_tensors="pt")
generation_output = model.generate(**inputs, return_dict_in_generate=True, output_scores=True)
```

The `generation_output` object is a [`~generation.GenerateDecoderOnlyOutput`], as we can
see in the documentation of that class below, it means it has the following attributes:

- `sequences`: the generated sequences of tokens
- `scores` (optional): the prediction scores of the language modelling head, for each generation step
- `hidden_states` (optional): the hidden states of the model, for each generation step
- `attentions` (optional): the attention weights of the model, for each generation step

Here we have the `scores` since we passed along `output_scores=True`, but we don't have `hidden_states` and
`attentions` because we didn't pass `output_hidden_states=True` or `output_attentions=True`.

You can access each attribute as you would usually do, and if that attribute has not been returned by the model, you
will get `None`. Here for instance `generation_output.scores` are all the generated prediction scores of the
language modeling head, and `generation_output.attentions` is `None`.

When using our `generation_output` object as a tuple, it only keeps the attributes that don't have `None` values.
Here, for instance, it has two elements, `loss` then `logits`, so

```python
generation_output[:2]
```

will return the tuple `(generation_output.sequences, generation_output.scores)` for instance.

When using our `generation_output` object as a dictionary, it only keeps the attributes that don't have `None`
values. Here, for instance, it has two keys that are `sequences` and `scores`.

We document here all output types.

[[autodoc]] generation.GenerateDecoderOnlyOutput

[[autodoc]] generation.GenerateEncoderDecoderOutput

[[autodoc]] generation.GenerateBeamDecoderOnlyOutput

[[autodoc]] generation.GenerateBeamEncoderDecoderOutput

## LogitsProcessor

A [`LogitsProcessor`] can be used to modify the prediction scores of a language model head for
generation.

[[autodoc]] AlternatingCodebooksLogitsProcessor
    - __call__

[[autodoc]] ClassifierFreeGuidanceLogitsProcessor
    - __call__

[[autodoc]] EncoderNoRepeatNGramLogitsProcessor
    - __call__

[[autodoc]] EncoderRepetitionPenaltyLogitsProcessor
    - __call__

[[autodoc]] EpsilonLogitsWarper
    - __call__

[[autodoc]] EtaLogitsWarper
    - __call__

[[autodoc]] ExponentialDecayLengthPenalty
    - __call__

[[autodoc]] ForcedBOSTokenLogitsProcessor
    - __call__

[[autodoc]] ForcedEOSTokenLogitsProcessor
    - __call__

[[autodoc]] InfNanRemoveLogitsProcessor
    - __call__

[[autodoc]] LogitNormalization
    - __call__

[[autodoc]] LogitsProcessor
    - __call__

[[autodoc]] LogitsProcessorList
    - __call__

[[autodoc]] MinLengthLogitsProcessor
    - __call__

[[autodoc]] MinNewTokensLengthLogitsProcessor
    - __call__

[[autodoc]] MinPLogitsWarper
    - __call__

[[autodoc]] NoBadWordsLogitsProcessor
    - __call__

[[autodoc]] NoRepeatNGramLogitsProcessor
    - __call__

[[autodoc]] PrefixConstrainedLogitsProcessor
    - __call__

[[autodoc]] RepetitionPenaltyLogitsProcessor
    - __call__

[[autodoc]] SequenceBiasLogitsProcessor
    - __call__

[[autodoc]] SuppressTokensAtBeginLogitsProcessor
    - __call__

[[autodoc]] SuppressTokensLogitsProcessor
    - __call__

[[autodoc]] SynthIDTextWatermarkLogitsProcessor
    - __call__

[[autodoc]] TemperatureLogitsWarper
    - __call__

[[autodoc]] TopHLogitsWarper
    - __call__

[[autodoc]] TopKLogitsWarper
    - __call__

[[autodoc]] TopPLogitsWarper
    - __call__

[[autodoc]] TypicalLogitsWarper
    - __call__

[[autodoc]] UnbatchedClassifierFreeGuidanceLogitsProcessor
    - __call__

[[autodoc]] WhisperTimeStampLogitsProcessor
    - __call__

[[autodoc]] WatermarkLogitsProcessor
    - __call__

## StoppingCriteria

A [`StoppingCriteria`] can be used to change when to stop generation (other than EOS token). Please note that this is exclusively available to our PyTorch implementations.

[[autodoc]] StoppingCriteria
    - __call__

[[autodoc]] StoppingCriteriaList
    - __call__

[[autodoc]] MaxLengthCriteria
    - __call__

[[autodoc]] MaxTimeCriteria
    - __call__

[[autodoc]] StopStringCriteria
    - __call__

[[autodoc]] EosTokenCriteria
    - __call__

## Streamers

[[autodoc]] TextStreamer

[[autodoc]] TextIteratorStreamer

[[autodoc]] AsyncTextIteratorStreamer

## Caches

[[autodoc]] CacheLayerMixin
    - update
    - get_seq_length
    - get_mask_sizes
    - get_max_cache_shape
    - reset
    - reorder_cache
    - lazy_initialization

[[autodoc]] DynamicLayer
    - update
    - lazy_initialization
    - crop
    - batch_repeat_interleave
    - batch_select_indices

[[autodoc]] StaticLayer
    - update
    - lazy_initialization

[[autodoc]] StaticSlidingWindowLayer
    - update
    - lazy_initialization

[[autodoc]] QuantoQuantizedLayer
    - update
    - lazy_initialization

[[autodoc]] HQQQuantizedLayer
    - update
    - lazy_initialization

[[autodoc]] Cache
    - update
    - early_initialization
    - get_seq_length
    - get_mask_sizes
    - get_max_cache_shape
    - reset
    - reorder_cache
    - crop
    - batch_repeat_interleave
    - batch_select_indices

[[autodoc]] DynamicCache

[[autodoc]] StaticCache

[[autodoc]] QuantizedCache

[[autodoc]] EncoderDecoderCache

## Watermark Utils

[[autodoc]] WatermarkingConfig
    - __call__

[[autodoc]] WatermarkDetector
    - __call__

[[autodoc]] BayesianDetectorConfig

[[autodoc]] BayesianDetectorModel
    - forward

[[autodoc]] SynthIDTextWatermarkingConfig

[[autodoc]] SynthIDTextWatermarkDetector
    - __call__

## Compile Utils

[[autodoc]] CompileConfig
    - __call__