This package comprises the following classes that can be imported in Python and are detailed in the [Doc](#doc) section of this readme:
- Eight PyTorch models (`torch.nn.Module`) for Bert with pre-trained weights (in the [`modeling.py`](./pytorch_pretrained_bert/modeling.py) file):
-[`BertModel`](./pytorch_pretrained_bert/modeling.py#L537) - raw BERT Transformer model (**fully pre-trained**),
-[`BertForMaskedLM`](./pytorch_pretrained_bert/modeling.py#L691) - BERT Transformer with the pre-trained masked language modeling head on top (**fully pre-trained**),
-[`BertForNextSentencePrediction`](./pytorch_pretrained_bert/modeling.py#L752) - BERT Transformer with the pre-trained next sentence prediction classifier on top (**fully pre-trained**),
-[`BertForPreTraining`](./pytorch_pretrained_bert/modeling.py#L620) - BERT Transformer with masked language modeling head and next sentence prediction classifier on top (**fully pre-trained**),
-[`BertForSequenceClassification`](./pytorch_pretrained_bert/modeling.py#L814) - BERT Transformer with a sequence classification head on top (BERT Transformer is **pre-trained**, the sequence classification head **is only initialized and has to be trained**),
-[`BertForMultipleChoice`](./pytorch_pretrained_bert/modeling.py#L880) - BERT Transformer with a multiple choice head on top (used for task like Swag) (BERT Transformer is **pre-trained**, the multiple choice classification head **is only initialized and has to be trained**),
-[`BertForTokenClassification`](./pytorch_pretrained_bert/modeling.py#L949) - BERT Transformer with a token classification head on top (BERT Transformer is **pre-trained**, the token classification head **is only initialized and has to be trained**),
-[`BertForQuestionAnswering`](./pytorch_pretrained_bert/modeling.py#L1015) - BERT Transformer with a token classification head on top (BERT Transformer is **pre-trained**, the token classification head **is only initialized and has to be trained**).
-[`BertModel`](./pytorch_pretrained_bert/modeling.py#L556) - raw BERT Transformer model (**fully pre-trained**),
-[`BertForMaskedLM`](./pytorch_pretrained_bert/modeling.py#L710) - BERT Transformer with the pre-trained masked language modeling head on top (**fully pre-trained**),
-[`BertForNextSentencePrediction`](./pytorch_pretrained_bert/modeling.py#L771) - BERT Transformer with the pre-trained next sentence prediction classifier on top (**fully pre-trained**),
-[`BertForPreTraining`](./pytorch_pretrained_bert/modeling.py#L639) - BERT Transformer with masked language modeling head and next sentence prediction classifier on top (**fully pre-trained**),
-[`BertForSequenceClassification`](./pytorch_pretrained_bert/modeling.py#L833) - BERT Transformer with a sequence classification head on top (BERT Transformer is **pre-trained**, the sequence classification head **is only initialized and has to be trained**),
-[`BertForMultipleChoice`](./pytorch_pretrained_bert/modeling.py#L899) - BERT Transformer with a multiple choice head on top (used for task like Swag) (BERT Transformer is **pre-trained**, the multiple choice classification head **is only initialized and has to be trained**),
-[`BertForTokenClassification`](./pytorch_pretrained_bert/modeling.py#L969) - BERT Transformer with a token classification head on top (BERT Transformer is **pre-trained**, the token classification head **is only initialized and has to be trained**),
-[`BertForQuestionAnswering`](./pytorch_pretrained_bert/modeling.py#L1034) - BERT Transformer with a token classification head on top (BERT Transformer is **pre-trained**, the token classification head **is only initialized and has to be trained**).
- Three tokenizers (in the [`tokenization.py`](./pytorch_pretrained_bert/tokenization.py) file):