added best practices for serialization in README and examples

pytorch_pretrained_bert/__init__.py

@@ -21,4 +21,4 @@ from .modeling_gpt2 import (GPT2Config, GPT2Model,
 from .optimization import BertAdam
 from .optimization_openai import OpenAIAdam
 
-from .file_utils import PYTORCH_PRETRAINED_BERT_CACHE, cached_path
+from .file_utils import PYTORCH_PRETRAINED_BERT_CACHE, cached_path, WEIGHTS_NAME, CONFIG_NAME

pytorch_pretrained_bert/file_utils.py

@@ -33,6 +33,9 @@ except (AttributeError, ImportError):
     PYTORCH_PRETRAINED_BERT_CACHE = os.getenv('PYTORCH_PRETRAINED_BERT_CACHE',
                                               os.path.join(os.path.expanduser("~"), '.pytorch_pretrained_bert'))
 
+CONFIG_NAME = "config.json"
+WEIGHTS_NAME = "pytorch_model.bin"
+
 logger = logging.getLogger(__name__)  # pylint: disable=invalid-name
 
 

pytorch_pretrained_bert/modeling.py

@@ -32,7 +32,7 @@ import torch
 from torch import nn
 from torch.nn import CrossEntropyLoss
 
-from .file_utils import cached_path
+from .file_utils import cached_path, WEIGHTS_NAME, CONFIG_NAME
 
 logger = logging.getLogger(__name__)
 
@@ -45,8 +45,7 @@ PRETRAINED_MODEL_ARCHIVE_MAP = {
     'bert-base-multilingual-cased': "https://s3.amazonaws.com/models.huggingface.co/bert/bert-base-multilingual-cased.tar.gz",
     'bert-base-chinese': "https://s3.amazonaws.com/models.huggingface.co/bert/bert-base-chinese.tar.gz",
 }
-CONFIG_NAME = 'bert_config.json'
-WEIGHTS_NAME = 'pytorch_model.bin'
+BERT_CONFIG_NAME = 'bert_config.json'
 TF_WEIGHTS_NAME = 'model.ckpt'
 
 def load_tf_weights_in_bert(model, tf_checkpoint_path):
@@ -586,6 +585,9 @@ class BertPreTrainedModel(nn.Module):
             serialization_dir = tempdir
         # Load config
         config_file = os.path.join(serialization_dir, CONFIG_NAME)
+        if not os.path.exists(config_file):
+            # Backward compatibility with old naming format
+            config_file = os.path.join(serialization_dir, BERT_CONFIG_NAME)
         config = BertConfig.from_json_file(config_file)
         logger.info("Model config {}".format(config))
         # Instantiate model.

pytorch_pretrained_bert/modeling_gpt2.py

@@ -34,7 +34,7 @@ import torch.nn as nn
 from torch.nn import CrossEntropyLoss
 from torch.nn.parameter import Parameter
 
-from .file_utils import cached_path
+from .file_utils import cached_path, CONFIG_NAME, WEIGHTS_NAME
 from .modeling import BertLayerNorm as LayerNorm
 
 logger = logging.getLogger(__name__)
@@ -42,9 +42,6 @@ logger = logging.getLogger(__name__)
 PRETRAINED_MODEL_ARCHIVE_MAP = {"gpt2": "https://s3.amazonaws.com/models.huggingface.co/bert/gpt2-pytorch_model.bin"}
 PRETRAINED_CONFIG_ARCHIVE_MAP = {"gpt2": "https://s3.amazonaws.com/models.huggingface.co/bert/gpt2-config.json"}
 
-CONFIG_NAME = "config.json"
-WEIGHTS_NAME = "pytorch_model.bin"
-
 def load_tf_weights_in_gpt2(model, gpt2_checkpoint_path):
     """ Load tf checkpoints in a pytorch model
     """

pytorch_pretrained_bert/modeling_openai.py

@@ -34,7 +34,7 @@ import torch.nn as nn
 from torch.nn import CrossEntropyLoss
 from torch.nn.parameter import Parameter
 
-from .file_utils import cached_path
+from .file_utils import cached_path, CONFIG_NAME, WEIGHTS_NAME
 from .modeling import BertLayerNorm as LayerNorm
 
 logger = logging.getLogger(__name__)
@@ -42,8 +42,6 @@ logger = logging.getLogger(__name__)
 PRETRAINED_MODEL_ARCHIVE_MAP = {"openai-gpt": "https://s3.amazonaws.com/models.huggingface.co/bert/openai-gpt-pytorch_model.bin"}
 PRETRAINED_CONFIG_ARCHIVE_MAP = {"openai-gpt": "https://s3.amazonaws.com/models.huggingface.co/bert/openai-gpt-config.json"}
 
-CONFIG_NAME = "config.json"
-WEIGHTS_NAME = "pytorch_model.bin"
 
 def load_tf_weights_in_openai_gpt(model, openai_checkpoint_folder_path):
     """ Load tf pre-trained weights in a pytorch model (from NumPy arrays here)

pytorch_pretrained_bert/modeling_transfo_xl.py

@@ -40,7 +40,7 @@ from torch.nn.parameter import Parameter
 
 from .modeling import BertLayerNorm as LayerNorm
 from .modeling_transfo_xl_utilities import ProjectedAdaptiveLogSoftmax, sample_logits
-from .file_utils import cached_path
+from .file_utils import cached_path, CONFIG_NAME, WEIGHTS_NAME
 
 logger = logging.getLogger(__name__)
 
@@ -50,8 +50,7 @@ PRETRAINED_MODEL_ARCHIVE_MAP = {
 PRETRAINED_CONFIG_ARCHIVE_MAP = {
     'transfo-xl-wt103': "https://s3.amazonaws.com/models.huggingface.co/bert/transfo-xl-wt103-config.json",
 }
-CONFIG_NAME = 'config.json'
-WEIGHTS_NAME = 'pytorch_model.bin'
+
 TF_WEIGHTS_NAME = 'model.ckpt'
 
 def build_tf_to_pytorch_map(model, config):