模型输出
所有模型的输出都是 [~utils.ModelOutput] 的子类的实例。这些是包含模型返回的所有信息的数据结构，但也可以用作元组或字典。
让我们看一个例子：
from transformers import BertTokenizer, BertForSequenceClassification
import torch
tokenizer = BertTokenizer.from_pretrained("google-bert/bert-base-uncased")
model = BertForSequenceClassification.from_pretrained("google-bert/bert-base-uncased")
inputs = tokenizer("Hello, my dog is cute", return_tensors="pt")
labels = torch.tensor([1]).unsqueeze(0) # Batch size 1
outputs = model(**inputs, labels=labels)
outputs 对象是 [~modeling_outputs.SequenceClassifierOutput]，如下面该类的文档中所示，它表示它有一个可选的 loss，一个 logits，一个可选的 hidden_states 和一个可选的 attentions 属性。在这里，我们有 loss，因为我们传递了 labels，但我们没有 hidden_states 和 attentions，因为我们没有传递 output_hidden_states=True 或 output_attentions=True。
当传递 output_hidden_states=True 时，您可能希望 outputs.hidden_states[-1] 与 outputs.last_hidden_states 完全匹配。然而，这并不总是成立。一些模型在返回最后的 hidden state时对其应用归一化或其他后续处理。
您可以像往常一样访问每个属性，如果模型未返回该属性，您将得到 None。在这里，例如，outputs.loss 是模型计算的损失，而 outputs.attentions 是 None。
当将我们的 outputs 对象视为元组时，它仅考虑那些没有 None 值的属性。例如这里它有两个元素，loss 和 logits，所以
outputs[:2]
将返回元组 (outputs.loss, outputs.logits)。
将我们的 outputs 对象视为字典时，它仅考虑那些没有 None 值的属性。例如在这里它有两个键，分别是 loss 和 logits。
我们在这里记录了被多个类型模型使用的通用模型输出。特定输出类型在其相应的模型页面上有文档。
ModelOutput
[[autodoc]] utils.ModelOutput - to_tuple
BaseModelOutput
[[autodoc]] modeling_outputs.BaseModelOutput
BaseModelOutputWithPooling
[[autodoc]] modeling_outputs.BaseModelOutputWithPooling
BaseModelOutputWithCrossAttentions
[[autodoc]] modeling_outputs.BaseModelOutputWithCrossAttentions
BaseModelOutputWithPoolingAndCrossAttentions
[[autodoc]] modeling_outputs.BaseModelOutputWithPoolingAndCrossAttentions
BaseModelOutputWithPast
[[autodoc]] modeling_outputs.BaseModelOutputWithPast
BaseModelOutputWithPastAndCrossAttentions
[[autodoc]] modeling_outputs.BaseModelOutputWithPastAndCrossAttentions
Seq2SeqModelOutput
[[autodoc]] modeling_outputs.Seq2SeqModelOutput
CausalLMOutput
[[autodoc]] modeling_outputs.CausalLMOutput
CausalLMOutputWithCrossAttentions
[[autodoc]] modeling_outputs.CausalLMOutputWithCrossAttentions
CausalLMOutputWithPast
[[autodoc]] modeling_outputs.CausalLMOutputWithPast
MaskedLMOutput
[[autodoc]] modeling_outputs.MaskedLMOutput
Seq2SeqLMOutput
[[autodoc]] modeling_outputs.Seq2SeqLMOutput
NextSentencePredictorOutput
[[autodoc]] modeling_outputs.NextSentencePredictorOutput
SequenceClassifierOutput
[[autodoc]] modeling_outputs.SequenceClassifierOutput
Seq2SeqSequenceClassifierOutput
[[autodoc]] modeling_outputs.Seq2SeqSequenceClassifierOutput
MultipleChoiceModelOutput
[[autodoc]] modeling_outputs.MultipleChoiceModelOutput
TokenClassifierOutput
[[autodoc]] modeling_outputs.TokenClassifierOutput
QuestionAnsweringModelOutput
[[autodoc]] modeling_outputs.QuestionAnsweringModelOutput
Seq2SeqQuestionAnsweringModelOutput
[[autodoc]] modeling_outputs.Seq2SeqQuestionAnsweringModelOutput
Seq2SeqSpectrogramOutput
[[autodoc]] modeling_outputs.Seq2SeqSpectrogramOutput
SemanticSegmenterOutput
[[autodoc]] modeling_outputs.SemanticSegmenterOutput
ImageClassifierOutput
[[autodoc]] modeling_outputs.ImageClassifierOutput
ImageClassifierOutputWithNoAttention
[[autodoc]] modeling_outputs.ImageClassifierOutputWithNoAttention
DepthEstimatorOutput
[[autodoc]] modeling_outputs.DepthEstimatorOutput
Wav2Vec2BaseModelOutput
[[autodoc]] modeling_outputs.Wav2Vec2BaseModelOutput
XVectorOutput
[[autodoc]] modeling_outputs.XVectorOutput
Seq2SeqTSModelOutput
[[autodoc]] modeling_outputs.Seq2SeqTSModelOutput
Seq2SeqTSPredictionOutput
[[autodoc]] modeling_outputs.Seq2SeqTSPredictionOutput
SampleTSPredictionOutput
[[autodoc]] modeling_outputs.SampleTSPredictionOutput
TFBaseModelOutput
[[autodoc]] modeling_tf_outputs.TFBaseModelOutput
TFBaseModelOutputWithPooling
[[autodoc]] modeling_tf_outputs.TFBaseModelOutputWithPooling
TFBaseModelOutputWithPoolingAndCrossAttentions
[[autodoc]] modeling_tf_outputs.TFBaseModelOutputWithPoolingAndCrossAttentions
TFBaseModelOutputWithPast
[[autodoc]] modeling_tf_outputs.TFBaseModelOutputWithPast
TFBaseModelOutputWithPastAndCrossAttentions
[[autodoc]] modeling_tf_outputs.TFBaseModelOutputWithPastAndCrossAttentions
TFSeq2SeqModelOutput
[[autodoc]] modeling_tf_outputs.TFSeq2SeqModelOutput
TFCausalLMOutput
[[autodoc]] modeling_tf_outputs.TFCausalLMOutput
TFCausalLMOutputWithCrossAttentions
[[autodoc]] modeling_tf_outputs.TFCausalLMOutputWithCrossAttentions
TFCausalLMOutputWithPast
[[autodoc]] modeling_tf_outputs.TFCausalLMOutputWithPast
TFMaskedLMOutput
[[autodoc]] modeling_tf_outputs.TFMaskedLMOutput
TFSeq2SeqLMOutput
[[autodoc]] modeling_tf_outputs.TFSeq2SeqLMOutput
TFNextSentencePredictorOutput
[[autodoc]] modeling_tf_outputs.TFNextSentencePredictorOutput
TFSequenceClassifierOutput
[[autodoc]] modeling_tf_outputs.TFSequenceClassifierOutput
TFSeq2SeqSequenceClassifierOutput
[[autodoc]] modeling_tf_outputs.TFSeq2SeqSequenceClassifierOutput
TFMultipleChoiceModelOutput
[[autodoc]] modeling_tf_outputs.TFMultipleChoiceModelOutput
TFTokenClassifierOutput
[[autodoc]] modeling_tf_outputs.TFTokenClassifierOutput
TFQuestionAnsweringModelOutput
[[autodoc]] modeling_tf_outputs.TFQuestionAnsweringModelOutput
TFSeq2SeqQuestionAnsweringModelOutput
[[autodoc]] modeling_tf_outputs.TFSeq2SeqQuestionAnsweringModelOutput
FlaxBaseModelOutput
[[autodoc]] modeling_flax_outputs.FlaxBaseModelOutput
FlaxBaseModelOutputWithPast
[[autodoc]] modeling_flax_outputs.FlaxBaseModelOutputWithPast
FlaxBaseModelOutputWithPooling
[[autodoc]] modeling_flax_outputs.FlaxBaseModelOutputWithPooling
FlaxBaseModelOutputWithPastAndCrossAttentions
[[autodoc]] modeling_flax_outputs.FlaxBaseModelOutputWithPastAndCrossAttentions
FlaxSeq2SeqModelOutput
[[autodoc]] modeling_flax_outputs.FlaxSeq2SeqModelOutput
FlaxCausalLMOutputWithCrossAttentions
[[autodoc]] modeling_flax_outputs.FlaxCausalLMOutputWithCrossAttentions
FlaxMaskedLMOutput
[[autodoc]] modeling_flax_outputs.FlaxMaskedLMOutput
FlaxSeq2SeqLMOutput
[[autodoc]] modeling_flax_outputs.FlaxSeq2SeqLMOutput
FlaxNextSentencePredictorOutput
[[autodoc]] modeling_flax_outputs.FlaxNextSentencePredictorOutput
FlaxSequenceClassifierOutput
[[autodoc]] modeling_flax_outputs.FlaxSequenceClassifierOutput
FlaxSeq2SeqSequenceClassifierOutput
[[autodoc]] modeling_flax_outputs.FlaxSeq2SeqSequenceClassifierOutput
FlaxMultipleChoiceModelOutput
[[autodoc]] modeling_flax_outputs.FlaxMultipleChoiceModelOutput
FlaxTokenClassifierOutput
[[autodoc]] modeling_flax_outputs.FlaxTokenClassifierOutput
FlaxQuestionAnsweringModelOutput
[[autodoc]] modeling_flax_outputs.FlaxQuestionAnsweringModelOutput
FlaxSeq2SeqQuestionAnsweringModelOutput
[[autodoc]] modeling_flax_outputs.FlaxSeq2SeqQuestionAnsweringModelOutput