model in evaluation mode by default after from_pretrained

README.md

@@ -102,10 +102,6 @@ Let's see how we can use `BertModel` to encode our inputs in hidden-states:
 # Load pre-trained model (weights)
 model = BertModel.from_pretrained('bert-base-uncased')
 
-# Set the model in evaluation mode to desactivate the DropOut modules
-# This is IMPORTANT to have reproductible results during evaluation!
-model.eval()
-
 # If you have a GPU, put everything on cuda
 tokens_tensor = tokens_tensor.to('cuda')
 segments_tensors = segments_tensors.to('cuda')
@@ -129,7 +125,6 @@ And how to use `BertForMaskedLM` to predict a masked token:
 ```python
 # Load pre-trained model (weights)
 model = BertForMaskedLM.from_pretrained('bert-base-uncased')
-model.eval()
 
 # If you have a GPU, put everything on cuda
 tokens_tensor = tokens_tensor.to('cuda')
@@ -178,10 +173,6 @@ Let's see how to use `GPT2LMHeadModel` to generate the next token following our
 # Load pre-trained model (weights)
 model = GPT2LMHeadModel.from_pretrained('gpt2')
 
-# Set the model in evaluation mode to desactivate the DropOut modules
-# This is IMPORTANT to have reproductible results during evaluation!
-model.eval()
-
 # If you have a GPU, put everything on cuda
 tokens_tensor = tokens_tensor.to('cuda')
 model.to('cuda')

pytorch_transformers/modeling_utils.py

@@ -306,7 +306,10 @@ class PreTrainedModel(nn.Module):
 
     @classmethod
     def from_pretrained(cls, pretrained_model_name_or_path, *inputs, **kwargs):
-        r""" Instantiate a PretrainedConfig from a pre-trained model configuration.
+        r"""Instantiate a pretrained pytorch model from a pre-trained model configuration.
+
+            The model is set in evaluation mode by default using `model.eval()` (Dropout modules are desactivated)
+            To train the model, you should first set it back in training mode with `model.train()`
 
         Params:
             **pretrained_model_name_or_path**: either:
@@ -460,6 +463,9 @@ class PreTrainedModel(nn.Module):
         if hasattr(model, 'tie_weights'):
             model.tie_weights()  # make sure word embedding weights are still tied
 
+        # Set model in evaluation mode to desactivate DropOut modules by default
+        model.eval()
+
         if output_loading_info:
             loading_info = {"missing_keys": missing_keys, "unexpected_keys": unexpected_keys, "error_msgs": error_msgs}
             return model, loading_info