Added multiple AutoModel classes: AutoModelWithLMHead, AutoModelForQuestionAnswering and AutoModelForSequenceClassification

pytorch_transformers/__init__.py

@@ -10,7 +10,8 @@ from .tokenization_roberta import RobertaTokenizer
 
 from .tokenization_utils import (PreTrainedTokenizer)
 
-from .modeling_auto import (AutoConfig, AutoModel)
+from .modeling_auto import (AutoConfig, AutoModel, AutoModelForSequenceClassification, AutoModelForQuestionAnswering,
+                            AutoModelWithLMHead)
 
 from .modeling_bert import (BertConfig, BertPreTrainedModel, BertModel, BertForPreTraining,
                             BertForMaskedLM, BertForNextSentencePrediction,

pytorch_transformers/modeling_auto.py

@@ -23,13 +23,13 @@ import torch.nn as nn
 from torch.nn import CrossEntropyLoss, MSELoss
 from torch.nn.parameter import Parameter
 
-from .modeling_bert import BertConfig, BertModel
+from .modeling_bert import BertConfig, BertModel, BertForMaskedLM, BertForSequenceClassification, BertForQuestionAnswering
-from .modeling_openai import OpenAIGPTConfig, OpenAIGPTModel
+from .modeling_openai import OpenAIGPTConfig, OpenAIGPTModel, OpenAIGPTLMHeadModel
-from .modeling_gpt2 import GPT2Config, GPT2Model
+from .modeling_gpt2 import GPT2Config, GPT2Model, GPT2LMHeadModel
-from .modeling_transfo_xl import TransfoXLConfig, TransfoXLModel
+from .modeling_transfo_xl import TransfoXLConfig, TransfoXLModel, TransfoXLLMHeadModel
-from .modeling_xlnet import XLNetConfig, XLNetModel
+from .modeling_xlnet import XLNetConfig, XLNetModel, XLNetLMHeadModel, XLNetForSequenceClassification, XLNetForQuestionAnswering
-from .modeling_xlm import XLMConfig, XLMModel
+from .modeling_xlm import XLMConfig, XLMModel, XLMWithLMHeadModel, XLMForSequenceClassification, XLMForQuestionAnswering
-from .modeling_roberta import RobertaConfig, RobertaModel
+from .modeling_roberta import RobertaConfig, RobertaModel, RobertaForMaskedLM, RobertaForSequenceClassification
 
 from .modeling_utils import PreTrainedModel, SequenceSummary
 
@@ -137,20 +137,20 @@ class AutoModel(object):
         when created with the `AutoModel.from_pretrained(pretrained_model_name_or_path)`
         class method.
 
-        The `from_pretrained()` method take care of returning the correct model class instance
+        The `from_pretrained()` method takes care of returning the correct model class instance
         using pattern matching on the `pretrained_model_name_or_path` string.
 
         The base model class to instantiate is selected as the first pattern matching
         in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaModel (RoBERTa model)
             - contains `bert`: BertModel (Bert model)
             - contains `openai-gpt`: OpenAIGPTModel (OpenAI GPT model)
             - contains `gpt2`: GPT2Model (OpenAI GPT-2 model)
             - contains `transfo-xl`: TransfoXLModel (Transformer-XL model)
             - contains `xlnet`: XLNetModel (XLNet model)
             - contains `xlm`: XLMModel (XLM model)
-            - contains `roberta`: RobertaModel (RoBERTa model)
 
-        This class cannot be instantiated using `__init__()` (throw an error).
+        This class cannot be instantiated using `__init__()` (throws an error).
     """
     def __init__(self):
         raise EnvironmentError("AutoModel is designed to be instantiated "
@@ -158,18 +158,18 @@ class AutoModel(object):
 
     @classmethod
     def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
-        r""" Instantiate a one of the base model classes of the library
+        r""" Instantiates one of the base model classes of the library
         from a pre-trained model configuration.
 
         The base model class to instantiate is selected as the first pattern matching
         in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaModel (RoBERTa model)
             - contains `bert`: BertModel (Bert model)
             - contains `openai-gpt`: OpenAIGPTModel (OpenAI GPT model)
             - contains `gpt2`: GPT2Model (OpenAI GPT-2 model)
             - contains `transfo-xl`: TransfoXLModel (Transformer-XL model)
             - contains `xlnet`: XLNetModel (XLNet model)
             - contains `xlm`: XLMModel (XLM model)
-            - contains `roberta`: RobertaModel (RoBERTa model)
 
             The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated)
             To train the model, you should first set it back in training mode with `model.train()`
@@ -186,12 +186,12 @@ class AutoModel(object):
                     checkpoint in a PyTorch model using the provided conversion scripts and loading
                     the PyTorch model afterwards.
             **model_args**: (`optional`) Sequence:
-                All remaning positional arguments will be passed to the underlying model's __init__ function
+                All remaining positional arguments will be passed to the underlying model's __init__ function
-            **config**: an optional configuration for the model to use instead of an automatically loaded configuation.
+            **config**: an optional configuration for the model to use instead of an automatically loaded configuration.
                 Configuration can be automatically loaded when:
                 - the model is a model provided by the library (loaded with a `shortcut name` of a pre-trained model), or
-                - the model was saved using the `save_pretrained(save_directory)` (loaded by suppling the save directory).
+                - the model was saved using the `save_pretrained(save_directory)` (loaded by supplying the save directory).
-            **state_dict**: an optional state dictionnary for the model to use instead of a state dictionary loaded
+            **state_dict**: an optional state dictionary for the model to use instead of a state dictionary loaded
                 from saved weights file.
                 This option can be used if you want to create a model from a pretrained configuration but load your own weights.
                 In this case though, you should check if using `save_pretrained(dir)` and `from_pretrained(save_directory)` is not
@@ -200,7 +200,7 @@ class AutoModel(object):
                 Path to a directory in which a downloaded pre-trained model
                 configuration should be cached if the standard cache should not be used.
             **output_loading_info**: (`optional`) boolean:
-                Set to ``True`` to also return a dictionnary containing missing keys, unexpected keys and error messages.
+                Set to ``True`` to also return a dictionary containing missing keys, unexpected keys and error messages.
             **kwargs**: (`optional`) dict:
                 Dictionary of key, values to update the configuration object after loading.
                 Can be used to override selected configuration parameters. E.g. ``output_attention=True``.
@@ -243,3 +243,328 @@ class AutoModel(object):
         raise ValueError("Unrecognized model identifier in {}. Should contains one of "
                          "'bert', 'openai-gpt', 'gpt2', 'transfo-xl', 'xlnet', "
                          "'xlm', 'roberta'".format(pretrained_model_name_or_path))
+
+
+
+class AutoModelWithLMHead(object):
+    r"""
+        :class:`~pytorch_transformers.AutoModelWithLMHead` is a generic model class
+        that will be instantiated as one of the language modeling model classes of the library
+        when created with the `AutoModelWithLMHead.from_pretrained(pretrained_model_name_or_path)`
+        class method.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaForMaskedLM (RoBERTa model)
+            - contains `bert`: BertForMaskedLM (Bert model)
+            - contains `openai-gpt`: OpenAIGPTLMHeadModel (OpenAI GPT model)
+            - contains `gpt2`: GPT2LMHeadModel (OpenAI GPT-2 model)
+            - contains `transfo-xl`: TransfoXLLMHeadModel (Transformer-XL model)
+            - contains `xlnet`: XLNetLMHeadModel (XLNet model)
+            - contains `xlm`: XLMWithLMHeadModel (XLM model)
+
+        This class cannot be instantiated using `__init__()` (throws an error).
+    """
+    def __init__(self):
+        raise EnvironmentError("AutoModelWithLMHead is designed to be instantiated "
+            "using the `AutoModelWithLMHead.from_pretrained(pretrained_model_name_or_path)` method.")
+
+    @classmethod
+    def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
+        r""" Instantiates one of the language modeling model classes of the library
+        from a pre-trained model configuration.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaForMaskedLM (RoBERTa model)
+            - contains `bert`: BertForMaskedLM (Bert model)
+            - contains `openai-gpt`: OpenAIGPTLMHeadModel (OpenAI GPT model)
+            - contains `gpt2`: GPT2LMHeadModel (OpenAI GPT-2 model)
+            - contains `transfo-xl`: TransfoXLLMHeadModel (Transformer-XL model)
+            - contains `xlnet`: XLNetLMHeadModel (XLNet model)
+            - contains `xlm`: XLMWithLMHeadModel (XLM model)
+
+        The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated)
+        To train the model, you should first set it back in training mode with `model.train()`
+
+        Params:
+            **pretrained_model_name_or_path**: either:
+                - a string with the `shortcut name` of a pre-trained model to load from cache
+                    or download and cache if not already stored in cache (e.g. 'bert-base-uncased').
+                - a path to a `directory` containing a configuration file saved
+                    using the `save_pretrained(save_directory)` method.
+                - a path or url to a tensorflow index checkpoint `file` (e.g. `./tf_model/model.ckpt.index`).
+                    In this case, ``from_tf`` should be set to True and a configuration object should be
+                    provided as `config` argument. This loading option is slower than converting the TensorFlow
+                    checkpoint in a PyTorch model using the provided conversion scripts and loading
+                    the PyTorch model afterwards.
+            **model_args**: (`optional`) Sequence:
+                All remaining positional arguments will be passed to the underlying model's __init__ function
+            **config**: an optional configuration for the model to use instead of an automatically loaded configuration.
+                Configuration can be automatically loaded when:
+                - the model is a model provided by the library (loaded with a `shortcut name` of a pre-trained model), or
+                - the model was saved using the `save_pretrained(save_directory)` (loaded by supplying the save directory).
+            **state_dict**: an optional state dictionary for the model to use instead of a state dictionary loaded
+                from saved weights file.
+                This option can be used if you want to create a model from a pretrained configuration but load your own weights.
+                In this case though, you should check if using `save_pretrained(dir)` and `from_pretrained(save_directory)` is not
+                a simpler option.
+            **cache_dir**: (`optional`) string:
+                Path to a directory in which a downloaded pre-trained model
+                configuration should be cached if the standard cache should not be used.
+            **output_loading_info**: (`optional`) boolean:
+                Set to ``True`` to also return a dictionary containing missing keys, unexpected keys and error messages.
+            **kwargs**: (`optional`) dict:
+                Dictionary of key, values to update the configuration object after loading.
+                Can be used to override selected configuration parameters. E.g. ``output_attention=True``.
+
+               - If a configuration is provided with `config`, **kwargs will be directly passed
+                 to the underlying model's __init__ method.
+               - If a configuration is not provided, **kwargs will be first passed to the pretrained
+                 model configuration class loading function (`PretrainedConfig.from_pretrained`).
+                 Each key of **kwargs that corresponds to a configuration attribute
+                 will be used to override said attribute with the supplied **kwargs value.
+                 Remaining keys that do not correspond to any configuration attribute will
+                 be passed to the underlying model's __init__ function.
+
+        Examples::
+
+            model = AutoModelWithLMHead.from_pretrained('bert-base-uncased')    # Download model and configuration from S3 and cache.
+            model = AutoModelWithLMHead.from_pretrained('./test/bert_model/')  # E.g. model was saved using `save_pretrained('./test/saved_model/')`
+            model = AutoModelWithLMHead.from_pretrained('bert-base-uncased', output_attention=True)  # Update configuration during loading
+            assert model.config.output_attention == True
+            # Loading from a TF checkpoint file instead of a PyTorch model (slower)
+            config = AutoConfig.from_json_file('./tf_model/bert_tf_model_config.json')
+            model = AutoModelWithLMHead.from_pretrained('./tf_model/bert_tf_checkpoint.ckpt.index', from_tf=True, config=config)
+
+        """
+        if 'roberta' in pretrained_model_name_or_path:
+            return RobertaForMaskedLM.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'bert' in pretrained_model_name_or_path:
+            return BertForMaskedLM.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'openai-gpt' in pretrained_model_name_or_path:
+            return OpenAIGPTLMHeadModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'gpt2' in pretrained_model_name_or_path:
+            return GPT2LMHeadModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'transfo-xl' in pretrained_model_name_or_path:
+            return TransfoXLLMHeadModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlnet' in pretrained_model_name_or_path:
+            return XLNetLMHeadModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlm' in pretrained_model_name_or_path:
+            return XLMWithLMHeadModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+
+        raise ValueError("Unrecognized model identifier in {}. Should contains one of "
+                         "'bert', 'openai-gpt', 'gpt2', 'transfo-xl', 'xlnet', "
+                         "'xlm', 'roberta'".format(pretrained_model_name_or_path))
+
+
+class AutoModelForSequenceClassification(object):
+    r"""
+        :class:`~pytorch_transformers.AutoModelForSequenceClassification` is a generic model class
+        that will be instantiated as one of the sequence classification model classes of the library
+        when created with the `AutoModelForSequenceClassification.from_pretrained(pretrained_model_name_or_path)`
+        class method.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaForSequenceClassification (RoBERTa model)
+            - contains `bert`: BertForSequenceClassification (Bert model)
+            - contains `xlnet`: XLNetForSequenceClassification (XLNet model)
+            - contains `xlm`: XLMForSequenceClassification (XLM model)
+
+        This class cannot be instantiated using `__init__()` (throws an error).
+    """
+    def __init__(self):
+        raise EnvironmentError("AutoModelWithLMHead is designed to be instantiated "
+            "using the `AutoModelWithLMHead.from_pretrained(pretrained_model_name_or_path)` method.")
+
+    @classmethod
+    def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
+        r""" Instantiates one of the sequence classification model classes of the library
+        from a pre-trained model configuration.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `roberta`: RobertaForSequenceClassification (RoBERTa model)
+            - contains `bert`: BertForSequenceClassification (Bert model)
+            - contains `xlnet`: XLNetForSequenceClassification (XLNet model)
+            - contains `xlm`: XLMForSequenceClassification (XLM model)
+
+        The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated)
+        To train the model, you should first set it back in training mode with `model.train()`
+
+        Params:
+            **pretrained_model_name_or_path**: either:
+                - a string with the `shortcut name` of a pre-trained model to load from cache
+                    or download and cache if not already stored in cache (e.g. 'bert-base-uncased').
+                - a path to a `directory` containing a configuration file saved
+                    using the `save_pretrained(save_directory)` method.
+                - a path or url to a tensorflow index checkpoint `file` (e.g. `./tf_model/model.ckpt.index`).
+                    In this case, ``from_tf`` should be set to True and a configuration object should be
+                    provided as `config` argument. This loading option is slower than converting the TensorFlow
+                    checkpoint in a PyTorch model using the provided conversion scripts and loading
+                    the PyTorch model afterwards.
+            **model_args**: (`optional`) Sequence:
+                All remaining positional arguments will be passed to the underlying model's __init__ function
+            **config**: an optional configuration for the model to use instead of an automatically loaded configuration.
+                Configuration can be automatically loaded when:
+                - the model is a model provided by the library (loaded with a `shortcut name` of a pre-trained model), or
+                - the model was saved using the `save_pretrained(save_directory)` (loaded by supplying the save directory).
+            **state_dict**: an optional state dictionary for the model to use instead of a state dictionary loaded
+                from saved weights file.
+                This option can be used if you want to create a model from a pretrained configuration but load your own weights.
+                In this case though, you should check if using `save_pretrained(dir)` and `from_pretrained(save_directory)` is not
+                a simpler option.
+            **cache_dir**: (`optional`) string:
+                Path to a directory in which a downloaded pre-trained model
+                configuration should be cached if the standard cache should not be used.
+            **output_loading_info**: (`optional`) boolean:
+                Set to ``True`` to also return a dictionary containing missing keys, unexpected keys and error messages.
+            **kwargs**: (`optional`) dict:
+                Dictionary of key, values to update the configuration object after loading.
+                Can be used to override selected configuration parameters. E.g. ``output_attention=True``.
+
+               - If a configuration is provided with `config`, **kwargs will be directly passed
+                 to the underlying model's __init__ method.
+               - If a configuration is not provided, **kwargs will be first passed to the pretrained
+                 model configuration class loading function (`PretrainedConfig.from_pretrained`).
+                 Each key of **kwargs that corresponds to a configuration attribute
+                 will be used to override said attribute with the supplied **kwargs value.
+                 Remaining keys that do not correspond to any configuration attribute will
+                 be passed to the underlying model's __init__ function.
+
+        Examples::
+
+            model = AutoModelForSequenceClassification.from_pretrained('bert-base-uncased')    # Download model and configuration from S3 and cache.
+            model = AutoModelForSequenceClassification.from_pretrained('./test/bert_model/')  # E.g. model was saved using `save_pretrained('./test/saved_model/')`
+            model = AutoModelForSequenceClassification.from_pretrained('bert-base-uncased', output_attention=True)  # Update configuration during loading
+            assert model.config.output_attention == True
+            # Loading from a TF checkpoint file instead of a PyTorch model (slower)
+            config = AutoConfig.from_json_file('./tf_model/bert_tf_model_config.json')
+            model = AutoModelForSequenceClassification.from_pretrained('./tf_model/bert_tf_checkpoint.ckpt.index', from_tf=True, config=config)
+
+        """
+        if 'roberta' in pretrained_model_name_or_path:
+            return RobertaForSequenceClassification.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'bert' in pretrained_model_name_or_path:
+            return BertForSequenceClassification.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlnet' in pretrained_model_name_or_path:
+            return XLNetForSequenceClassification.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlm' in pretrained_model_name_or_path:
+            return XLMForSequenceClassification.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+
+        raise ValueError("Unrecognized model identifier in {}. Should contains one of "
+                         "'bert', 'xlnet', 'xlm', 'roberta'".format(pretrained_model_name_or_path))
+
+
+class AutoModelForQuestionAnswering(object):
+    r"""
+        :class:`~pytorch_transformers.AutoModelForQuestionAnswering` is a generic model class
+        that will be instantiated as one of the question answering model classes of the library
+        when created with the `AutoModelForQuestionAnswering.from_pretrained(pretrained_model_name_or_path)`
+        class method.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `bert`: BertForQuestionAnswering (Bert model)
+            - contains `xlnet`: XLNetForQuestionAnswering (XLNet model)
+            - contains `xlm`: XLMForQuestionAnswering (XLM model)
+
+        This class cannot be instantiated using `__init__()` (throws an error).
+    """
+    def __init__(self):
+        raise EnvironmentError("AutoModelWithLMHead is designed to be instantiated "
+            "using the `AutoModelWithLMHead.from_pretrained(pretrained_model_name_or_path)` method.")
+
+    @classmethod
+    def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
+        r""" Instantiates one of the question answering model classes of the library
+        from a pre-trained model configuration.
+
+        The `from_pretrained()` method takes care of returning the correct model class instance
+        using pattern matching on the `pretrained_model_name_or_path` string.
+
+        The model class to instantiate is selected as the first pattern matching
+        in the `pretrained_model_name_or_path` string (in the following order):
+            - contains `bert`: BertForQuestionAnswering (Bert model)
+            - contains `xlnet`: XLNetForQuestionAnswering (XLNet model)
+            - contains `xlm`: XLMForQuestionAnswering (XLM model)
+
+        The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated)
+        To train the model, you should first set it back in training mode with `model.train()`
+
+        Params:
+            **pretrained_model_name_or_path**: either:
+                - a string with the `shortcut name` of a pre-trained model to load from cache
+                    or download and cache if not already stored in cache (e.g. 'bert-base-uncased').
+                - a path to a `directory` containing a configuration file saved
+                    using the `save_pretrained(save_directory)` method.
+                - a path or url to a tensorflow index checkpoint `file` (e.g. `./tf_model/model.ckpt.index`).
+                    In this case, ``from_tf`` should be set to True and a configuration object should be
+                    provided as `config` argument. This loading option is slower than converting the TensorFlow
+                    checkpoint in a PyTorch model using the provided conversion scripts and loading
+                    the PyTorch model afterwards.
+            **model_args**: (`optional`) Sequence:
+                All remaining positional arguments will be passed to the underlying model's __init__ function
+            **config**: an optional configuration for the model to use instead of an automatically loaded configuration.
+                Configuration can be automatically loaded when:
+                - the model is a model provided by the library (loaded with a `shortcut name` of a pre-trained model), or
+                - the model was saved using the `save_pretrained(save_directory)` (loaded by supplying the save directory).
+            **state_dict**: an optional state dictionary for the model to use instead of a state dictionary loaded
+                from saved weights file.
+                This option can be used if you want to create a model from a pretrained configuration but load your own weights.
+                In this case though, you should check if using `save_pretrained(dir)` and `from_pretrained(save_directory)` is not
+                a simpler option.
+            **cache_dir**: (`optional`) string:
+                Path to a directory in which a downloaded pre-trained model
+                configuration should be cached if the standard cache should not be used.
+            **output_loading_info**: (`optional`) boolean:
+                Set to ``True`` to also return a dictionary containing missing keys, unexpected keys and error messages.
+            **kwargs**: (`optional`) dict:
+                Dictionary of key, values to update the configuration object after loading.
+                Can be used to override selected configuration parameters. E.g. ``output_attention=True``.
+
+               - If a configuration is provided with `config`, **kwargs will be directly passed
+                 to the underlying model's __init__ method.
+               - If a configuration is not provided, **kwargs will be first passed to the pretrained
+                 model configuration class loading function (`PretrainedConfig.from_pretrained`).
+                 Each key of **kwargs that corresponds to a configuration attribute
+                 will be used to override said attribute with the supplied **kwargs value.
+                 Remaining keys that do not correspond to any configuration attribute will
+                 be passed to the underlying model's __init__ function.
+
+        Examples::
+
+            model = AutoModelForQuestionAnswering.from_pretrained('bert-base-uncased')    # Download model and configuration from S3 and cache.
+            model = AutoModelForQuestionAnswering.from_pretrained('./test/bert_model/')  # E.g. model was saved using `save_pretrained('./test/saved_model/')`
+            model = AutoModelForQuestionAnswering.from_pretrained('bert-base-uncased', output_attention=True)  # Update configuration during loading
+            assert model.config.output_attention == True
+            # Loading from a TF checkpoint file instead of a PyTorch model (slower)
+            config = AutoConfig.from_json_file('./tf_model/bert_tf_model_config.json')
+            model = AutoModelForQuestionAnswering.from_pretrained('./tf_model/bert_tf_checkpoint.ckpt.index', from_tf=True, config=config)
+
+        """
+        if 'bert' in pretrained_model_name_or_path:
+            return BertForQuestionAnswering.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlnet' in pretrained_model_name_or_path:
+            return XLNetForQuestionAnswering.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+        elif 'xlm' in pretrained_model_name_or_path:
+            return XLMForQuestionAnswering.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
+
+        raise ValueError("Unrecognized model identifier in {}. Should contains one of "
+                         "'bert', 'xlnet', 'xlm'".format(pretrained_model_name_or_path))