#
Processors

在 Transformers 库中，processors可以有两种不同的含义：

- 为多模态模型，例如Wav2Vec2（语音和文本）或CLIP（文本和视觉）预处理输入的对象
- 在库的旧版本中用于预处理GLUE或SQUAD数据的已弃用对象。

##
多模态processors

任何多模态模型都需要一个对象来编码或解码将多个模态（包括文本、视觉和音频）组合在一起的数据。这由称为processors的对象处理，这些processors将两个或多个处理对象组合在一起，例如tokenizers（用于文本模态），image processors（用于视觉）和feature extractors（用于音频）。

这些processors继承自以下实现保存和加载功能的基类：

###
class transformers.ProcessorMixin

< source >

( *args **kwargs )

This is a mixin used to provide saving/loading functionality for all processor classes.

####
apply_chat_template

< source >

( conversation: typing.List[typing.Dict[str, str]] chat_template: typing.Optional[str] = None tokenize: bool = False **kwargs )

Parameters

- conversation (`List[Dict, str, str]`) — The conversation to format.
- chat_template (`Optional[str]`, optional) — The Jinja template to use for formatting the conversation. If not provided, the tokenizer’s chat template is used.
- tokenize (`bool`, optional, defaults to `False`) — Whether to tokenize the output or not.
- **kwargs — Additional keyword arguments

Similar to the `apply_chat_template` method on tokenizers, this method applies a Jinja template to input conversations to turn them into a single tokenizable string.

####
from_args_and_dict

< source >

( args processor_dict: typing.Dict[str, typing.Any] **kwargs ) →
`~processing_utils.ProcessingMixin`

Parameters

- processor_dict (`Dict[str, Any]`) — Dictionary that will be used to instantiate the processor object. Such a dictionary can be retrieved from a pretrained checkpoint by leveraging the `~processing_utils.ProcessingMixin.to_dict` method.
- kwargs (`Dict[str, Any]`) — Additional parameters from which to initialize the processor object.

Returns

`~processing_utils.ProcessingMixin`

The processor object instantiated from those parameters.

Instantiates a type of `~processing_utils.ProcessingMixin` from a Python dictionary of parameters.

####
from_pretrained

< source >

( pretrained_model_name_or_path: typing.Union[str, os.PathLike] cache_dir: typing.Union[str, os.PathLike, NoneType] = None force_download: bool = False local_files_only: bool = False token: typing.Union[str, bool, NoneType] = None revision: str = 'main' **kwargs )

Parameters

- pretrained_model_name_or_path (`str` or `os.PathLike`) — This can be either:
  - a string, the model id of a pretrained feature_extractor hosted inside a model repo on huggingface.co.
  - a path to a directory containing a feature extractor file saved using the save_pretrained() method, e.g., `./my_model_directory/`.
  - a path or url to a saved feature extractor JSON file, e.g., `./my_model_directory/preprocessor_config.json`.
- **kwargs — Additional keyword arguments passed along to both from_pretrained() and `~tokenization_utils_base.PreTrainedTokenizer.from_pretrained`.

Instantiate a processor associated with a pretrained model.

This class method is simply calling the feature extractor from_pretrained(), image processor ImageProcessingMixin and the tokenizer `~tokenization_utils_base.PreTrainedTokenizer.from_pretrained` methods. Please refer to the docstrings of the methods above for more information.

####
get_processor_dict

< source >

( pretrained_model_name_or_path: typing.Union[str, os.PathLike] **kwargs ) →
`Tuple[Dict, Dict]`

Parameters

- pretrained_model_name_or_path (`str` or `os.PathLike`) — The identifier of the pre-trained checkpoint from which we want the dictionary of parameters.
- subfolder (`str`, optional, defaults to `""`) — In case the relevant files are located inside a subfolder of the model repo on huggingface.co, you can specify the folder name here.

Returns

`Tuple[Dict, Dict]`

The dictionary(ies) that will be used to instantiate the processor object.

From a `pretrained_model_name_or_path`, resolve to a dictionary of parameters, to be used for instantiating a processor of type `~processing_utils.ProcessingMixin` using `from_args_and_dict`.

####
post_process_image_text_to_text

< source >

( generated_outputs ) →
`List[str]`

Parameters

- generated_outputs (`torch.Tensor` or `np.ndarray`) — The output of the model `generate` function. The output is expected to be a tensor of shape `(batch_size, sequence_length)` or `(sequence_length,)`.

Returns

`List[str]`

The decoded text.

Post-process the output of a vlm to decode the text.

####
prepare_and_validate_optional_call_args

< source >

( *args )

Matches optional positional arguments to their corresponding names in `optional_call_args` in the processor class in the order they are passed to the processor call.

Note that this should only be used in the `__call__` method of the processors with special arguments. Special arguments are arguments that aren’t `text`, `images`, `audio`, nor `videos` but also aren’t passed to the tokenizer, image processor, etc. Examples of such processors are:

- `CLIPSegProcessor`
- `LayoutLMv2Processor`
- `OwlViTProcessor`

Also note that passing by position to the processor call is now deprecated and will be disallowed in future versions. We only have this for backward compatibility.

Example: Suppose that the processor class has `optional_call_args = ["arg_name_1", "arg_name_2"]`.

And we define the call method as:

    def __call__(
        self,
        text: str,
        images: Optional[ImageInput] = None,
        *arg,
        audio=None,
        videos=None,
    )

Then, if we call the processor as:

    images = [...]
    processor("What is common in these images?", images, arg_value_1, arg_value_2)

Then, this method will return:

    {
        "arg_name_1": arg_value_1,
        "arg_name_2": arg_value_2,
    }

which we could then pass as kwargs to `self._merge_kwargs`

####
push_to_hub

< source >

( repo_id: str use_temp_dir: typing.Optional[bool] = None commit_message: typing.Optional[str] = None private: typing.Optional[bool] = None token: typing.Union[bool, str, NoneType] = None max_shard_size: typing.Union[int, str, NoneType] = '5GB' create_pr: bool = False safe_serialization: bool = True revision: str = None commit_description: str = None tags: typing.Optional[typing.List[str]] = None **deprecated_kwargs )

Parameters

- repo_id (`str`) — The name of the repository you want to push your processor to. It should contain your organization name when pushing to a given organization.
- use_temp_dir (`bool`, optional) — Whether or not to use a temporary directory to store the files saved before they are pushed to the Hub. Will default to `True` if there is no directory named like `repo_id`, `False` otherwise.
- commit_message (`str`, optional) — Message to commit while pushing. Will default to `"Upload processor"`.
- private (`bool`, optional) — Whether to make the repo private. If `None` (default), the repo will be public unless the organization’s default is private. This value is ignored if the repo already exists.
- token (`bool` or `str`, optional) — The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated when running `huggingface-cli login` (stored in `~/.huggingface`). Will default to `True` if `repo_url` is not specified.
- max_shard_size (`int` or `str`, optional, defaults to `"5GB"`) — Only applicable for models. The maximum size for a checkpoint before being sharded. Checkpoints shard will then be each of size lower than this size. If expressed as a string, needs to be digits followed by a unit (like `"5MB"`). We default it to `"5GB"` so that users can easily load models on free-tier Google Colab instances without any CPU OOM issues.
- create_pr (`bool`, optional, defaults to `False`) — Whether or not to create a PR with the uploaded files or directly commit.
- safe_serialization (`bool`, optional, defaults to `True`) — Whether or not to convert the model weights in safetensors format for safer serialization.
- revision (`str`, optional) — Branch to push the uploaded files to.
- commit_description (`str`, optional) — The description of the commit that will be created
- tags (`List[str]`, optional) — List of tags to push on the Hub.

Upload the processor files to the 🤗 Model Hub.

Examples:

    from transformers import AutoProcessor

    processor = AutoProcessor.from_pretrained("google-bert/bert-base-cased")

    # Push the processor to your namespace with the name "my-finetuned-bert".
    processor.push_to_hub("my-finetuned-bert")

    # Push the processor to an organization with the name "my-finetuned-bert".
    processor.push_to_hub("huggingface/my-finetuned-bert")

####
register_for_auto_class

< source >

( auto_class = 'AutoProcessor' )

Parameters

- auto_class (`str` or `type`, optional, defaults to `"AutoProcessor"`) — The auto class to register this new feature extractor with.

Register this class with a given auto class. This should only be used for custom feature extractors as the ones in the library are already mapped with `AutoProcessor`.

This API is experimental and may have some slight breaking changes in the next releases.

####
save_pretrained

< source >

( save_directory push_to_hub: bool = False **kwargs )

Parameters

- save_directory (`str` or `os.PathLike`) — Directory where the feature extractor JSON file and the tokenizer files will be saved (directory will be created if it does not exist).
- push_to_hub (`bool`, optional, defaults to `False`) — Whether or not to push your model to the Hugging Face model hub after saving it. You can specify the repository you want to push to with `repo_id` (will default to the name of `save_directory` in your namespace).
- kwargs (`Dict[str, Any]`, optional) — Additional key word arguments passed along to the push_to_hub() method.

Saves the attributes of this processor (feature extractor, tokenizer…) in the specified directory so that it can be reloaded using the from_pretrained() method.

This class method is simply calling save_pretrained() and save_pretrained(). Please refer to the docstrings of the methods above for more information.

####
to_dict

< source >

( ) →
`Dict[str, Any]`

Returns

`Dict[str, Any]`

Dictionary of all the attributes that make up this processor instance.

Serializes this instance to a Python dictionary.

####
to_json_file

< source >

( json_file_path: typing.Union[str, os.PathLike] )

Parameters

- json_file_path (`str` or `os.PathLike`) — Path to the JSON file in which this processor instance’s parameters will be saved.

Save this instance to a JSON file.

####
to_json_string

< source >

( ) →
`str`

Returns

`str`

String containing all the attributes that make up this feature_extractor instance in JSON format.

Serializes this instance to a JSON string.

##
已弃用的processors

所有processor都遵循与 DataProcessor 相同的架构。processor返回一个 InputExample 列表。这些 InputExample 可以转换为 InputFeatures 以供输送到模型。

###
class transformers.DataProcessor

< source >

( )

Base class for data converters for sequence classification data sets.

####
get_dev_examples

< source >

( data_dir )

Gets a collection of InputExample for the dev set.

####
get_example_from_tensor_dict

< source >

( tensor_dict )

Parameters

- tensor_dict — Keys and values should match the corresponding Glue tensorflow_dataset examples.

Gets an example from a dict with tensorflow tensors.

####
get_labels

< source >

( )

Gets the list of labels for this data set.

####
get_test_examples

< source >

( data_dir )

Gets a collection of InputExample for the test set.

####
get_train_examples

< source >

( data_dir )

Gets a collection of InputExample for the train set.

####
tfds_map

< source >

( example )

Some tensorflow_datasets datasets are not formatted the same way the GLUE datasets are. This method converts examples to the correct format.

###
class transformers.InputExample

< source >

( guid: str text_a: str text_b: typing.Optional[str] = None label: typing.Optional[str] = None )

Parameters

- guid — Unique id for the example.
- text_a — string. The untokenized text of the first sequence. For single sequence tasks, only this sequence must be specified.
- text_b — (Optional) string. The untokenized text of the second sequence. Only must be specified for sequence pair tasks.
- label — (Optional) string. The label of the example. This should be specified for train and dev examples, but not for test examples.

A single training/test example for simple sequence classification.

####
to_json_string

< source >

( )

Serializes this instance to a JSON string.

###
class transformers.InputFeatures

< source >

( input_ids: typing.List[int] attention_mask: typing.Optional[typing.List[int]] = None token_type_ids: typing.Optional[typing.List[int]] = None label: typing.Union[int, float, NoneType] = None )

Parameters

- input_ids — Indices of input sequence tokens in the vocabulary.
- attention_mask — Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: Usually `1` for tokens that are NOT MASKED, `0` for MASKED (padded) tokens.
- token_type_ids — (Optional) Segment token indices to indicate first and second portions of the inputs. Only some models use them.
- label — (Optional) Label corresponding to the input. Int for classification problems, float for regression problems.

A single set of features of data. Property names are the same names as the corresponding inputs to a model.

####
to_json_string

< source >

( )

Serializes this instance to a JSON string.

##
GLUE

General Language Understanding Evaluation (GLUE) 是一个基准测试，评估模型在各种现有的自然语言理解任务上的性能。它与论文 GLUE: A multi-task benchmark and analysis platform for natural language understanding 一同发布。

该库为以下任务提供了总共10个processor：MRPC、MNLI、MNLI（mismatched）、CoLA、SST2、STSB、QQP、QNLI、RTE 和 WNLI。

这些processor是：

- `~data.processors.utils.MrpcProcessor`
- `~data.processors.utils.MnliProcessor`
- `~data.processors.utils.MnliMismatchedProcessor`
- `~data.processors.utils.Sst2Processor`
- `~data.processors.utils.StsbProcessor`
- `~data.processors.utils.QqpProcessor`
- `~data.processors.utils.QnliProcessor`
- `~data.processors.utils.RteProcessor`
- `~data.processors.utils.WnliProcessor`

此外，还可以使用以下方法从数据文件加载值并将其转换为 InputExample 列表。

####
transformers.glue_convert_examples_to_features

< source >

( examples: typing.Union[typing.List[transformers.data.processors.utils.InputExample], ForwardRef('tf.data.Dataset')] tokenizer: PreTrainedTokenizer max_length: typing.Optional[int] = None task = None label_list = None output_mode = None )

Parameters

- examples — List of `InputExamples` or `tf.data.Dataset` containing the examples.
- tokenizer — Instance of a tokenizer that will tokenize the examples
- max_length — Maximum example length. Defaults to the tokenizer’s max_len
- task — GLUE task
- label_list — List of labels. Can be obtained from the processor using the `processor.get_labels()` method
- output_mode — String indicating the output mode. Either `regression` or `classification`

Loads a data file into a list of `InputFeatures`

##
XNLI

跨语言NLI语料库（XNLI） 是一个评估跨语言文本表示质量的基准测试。XNLI是一个基于MultiNLI的众包数据集：”文本对“被标记为包含15种不同语言（包括英语等高资源语言和斯瓦希里语等低资源语言）的文本蕴涵注释。

它与论文 XNLI: Evaluating Cross-lingual Sentence Representations 一同发布。

该库提供了加载XNLI数据的processor：

- `~data.processors.utils.XnliProcessor`

请注意，由于测试集上有“gold”标签，因此评估是在测试集上进行的。

使用这些processor的示例在 run_xnli.py 脚本中提供。

##
SQuAD

斯坦福问答数据集（SQuAD） 是一个评估模型在问答上性能的基准测试。有两个版本，v1.1 和 v2.0。第一个版本（v1.1）与论文 SQuAD: 100,000+ Questions for Machine Comprehension of Text 一同发布。第二个版本（v2.0）与论文 Know What You Don’t Know: Unanswerable Questions for SQuAD 一同发布。

该库为两个版本各自提供了一个processor：

###
Processors

这两个processor是：

- `~data.processors.utils.SquadV1Processor`
- `~data.processors.utils.SquadV2Processor`

它们都继承自抽象类 `~data.processors.utils.SquadProcessor`。

###
class transformers.data.processors.squad.SquadProcessor

< source >

( )

Processor for the SQuAD data set. overridden by SquadV1Processor and SquadV2Processor, used by the version 1.1 and version 2.0 of SQuAD, respectively.

####
get_dev_examples

< source >

( data_dir filename = None )

Parameters

- data_dir — Directory containing the data files used for training and evaluating.
- filename — None by default, specify this if the evaluation file has a different name than the original one which is `dev-v1.1.json` and `dev-v2.0.json` for squad versions 1.1 and 2.0 respectively.

Returns the evaluation example from the data directory.

####
get_examples_from_dataset

< source >

( dataset evaluate = False )

Parameters

- dataset — The tfds dataset loaded from tensorflow_datasets.load(“squad”)
- evaluate — Boolean specifying if in evaluation mode or in training mode

Creates a list of `SquadExample` using a TFDS dataset.

Examples:

    >>> import tensorflow_datasets as tfds

    >>> dataset = tfds.load("squad")

    >>> training_examples = get_examples_from_dataset(dataset, evaluate=False)
    >>> evaluation_examples = get_examples_from_dataset(dataset, evaluate=True)

####
get_train_examples

< source >

( data_dir filename = None )

Parameters

- data_dir — Directory containing the data files used for training and evaluating.
- filename — None by default, specify this if the training file has a different name than the original one which is `train-v1.1.json` and `train-v2.0.json` for squad versions 1.1 and 2.0 respectively.

Returns the training examples from the data directory.

此外，可以使用以下方法将 SQuAD 示例转换为可用作模型输入的 `~data.processors.utils.SquadFeatures`。

####
transformers.squad_convert_examples_to_features

< source >

( examples tokenizer max_seq_length doc_stride max_query_length is_training padding_strategy = 'max_length' return_dataset = False threads = 1 tqdm_enabled = True )

Parameters

- examples — list of `SquadExample`
- tokenizer — an instance of a child of PreTrainedTokenizer
- max_seq_length — The maximum sequence length of the inputs.
- doc_stride — The stride used when the context is too large and is split across several features.
- max_query_length — The maximum length of the query.
- is_training — whether to create features for model evaluation or model training.
- padding_strategy — Default to “max_length”. Which padding strategy to use
- return_dataset — Default False. Either ‘pt’ or ‘tf’. if ‘pt’: returns a torch.data.TensorDataset, if ‘tf’: returns a tf.data.Dataset
- threads — multiple processing threads.

Converts a list of examples into a list of features that can be directly given as input to a model. It is model-dependant and takes advantage of many of the tokenizer’s features to create the model’s inputs.

Example:

    processor = SquadV2Processor()
    examples = processor.get_dev_examples(data_dir)

    features = squad_convert_examples_to_features(
        examples=examples,
        tokenizer=tokenizer,
        max_seq_length=args.max_seq_length,
        doc_stride=args.doc_stride,
        max_query_length=args.max_query_length,
        is_training=not evaluate,
    )

这些processor以及前面提到的方法可以与包含数据的文件以及tensorflow_datasets包一起使用。下面给出了示例。

###
Example使用

以下是使用processor以及使用数据文件的转换方法的示例：

    # Loading a V2 processor
    processor = SquadV2Processor()
    examples = processor.get_dev_examples(squad_v2_data_dir)

    # Loading a V1 processor
    processor = SquadV1Processor()
    examples = processor.get_dev_examples(squad_v1_data_dir)

    features = squad_convert_examples_to_features(
        examples=examples,
        tokenizer=tokenizer,
        max_seq_length=max_seq_length,
        doc_stride=args.doc_stride,
        max_query_length=max_query_length,
        is_training=not evaluate,
    )

使用 tensorflow_datasets 就像使用数据文件一样简单：

    # tensorflow_datasets only handle Squad V1.
    tfds_examples = tfds.load("squad")
    examples = SquadV1Processor().get_examples_from_dataset(tfds_examples, evaluate=evaluate)

    features = squad_convert_examples_to_features(
        examples=examples,
        tokenizer=tokenizer,
        max_seq_length=max_seq_length,
        doc_stride=args.doc_stride,
        max_query_length=max_query_length,
        is_training=not evaluate,
    )

另一个使用这些processor的示例在 run_squad.py 脚本中提供。

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