Merge remote-tracking branch 'upstream/master'

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

@@ -5,11 +5,13 @@ Copyright by the AllenNLP authors.
 """
 from __future__ import (absolute_import, division, print_function, unicode_literals)
 
+import sys
 import json
 import logging
 import os
 import shutil
 import tempfile
+import fnmatch
 from functools import wraps
 from hashlib import sha256
 import sys
@@ -33,6 +35,9 @@ 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
 
 
@@ -188,17 +193,30 @@ def get_from_cache(url, cache_dir=None):
     if url.startswith("s3://"):
         etag = s3_etag(url)
     else:
-        response = requests.head(url, allow_redirects=True)
-        if response.status_code != 200:
-            raise IOError("HEAD request failed for url {} with status code {}"
-                          .format(url, response.status_code))
-        etag = response.headers.get("ETag")
+        try:
+            response = requests.head(url, allow_redirects=True)
+            if response.status_code != 200:
+                etag = None
+            else:
+                etag = response.headers.get("ETag")
+        except EnvironmentError:
+            etag = None
 
+    if sys.version_info[0] == 2 and etag is not None:
+        etag = etag.decode('utf-8')
     filename = url_to_filename(url, etag)
 
     # get cache path to put the file
     cache_path = os.path.join(cache_dir, filename)
 
+    # If we don't have a connection (etag is None) and can't identify the file
+    # try to get the last downloaded one
+    if not os.path.exists(cache_path) and etag is None:
+        matching_files = fnmatch.filter(os.listdir(cache_dir), filename + '.*')
+        matching_files = list(filter(lambda s: not s.endswith('.json'), matching_files))
+        if matching_files:
+            cache_path = os.path.join(cache_dir, matching_files[-1])
+
     if not os.path.exists(cache_path):
         # Download to temporary file, then copy to cache dir once finished.
         # Otherwise you get corrupt cache entries if the download gets interrupted.
@@ -223,8 +241,11 @@ def get_from_cache(url, cache_dir=None):
             logger.info("creating metadata file for %s", cache_path)
             meta = {'url': url, 'etag': etag}
             meta_path = cache_path + '.json'
-            with open(meta_path, 'w', encoding="utf-8") as meta_file:
-                json.dump(meta, meta_file)
+            with open(meta_path, 'w') as meta_file:
+                output_string = json.dumps(meta)
+                if sys.version_info[0] == 2 and isinstance(output_string, str):
+                    output_string = unicode(output_string, 'utf-8')  # The beauty of python 2
+                meta_file.write(output_string)
 
             logger.info("removing temp file %s", temp_file.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):
@@ -220,6 +219,11 @@ class BertConfig(object):
         """Serializes this instance to a JSON string."""
         return json.dumps(self.to_dict(), indent=2, sort_keys=True) + "\n"
 
+    def to_json_file(self, json_file_path):
+        """ Save this instance to a json file."""
+        with open(json_file_path, "w", encoding='utf-8') as writer:
+            writer.write(self.to_json_string())
+
 try:
     from apex.normalization.fused_layer_norm import FusedLayerNorm as BertLayerNorm
 except ImportError:
@@ -581,13 +585,16 @@ 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.
         model = cls(config, *inputs, **kwargs)
         if state_dict is None and not from_tf:
             weights_path = os.path.join(serialization_dir, WEIGHTS_NAME)
-            state_dict = torch.load(weights_path, map_location='cpu' if not torch.cuda.is_available() else None)
+            state_dict = torch.load(weights_path, map_location='cpu')
         if tempdir:
             # Clean up temp dir
             shutil.rmtree(tempdir)
@@ -930,7 +937,7 @@ class BertForSequenceClassification(BertPreTrainedModel):
 
     Inputs:
         `input_ids`: a torch.LongTensor of shape [batch_size, sequence_length]
-            with the word token indices in the vocabulary(see the tokens preprocessing logic in the scripts
+            with the word token indices in the vocabulary. Items in the batch should begin with the special "CLS" token. (see the tokens preprocessing logic in the scripts
             `extract_features.py`, `run_classifier.py` and `run_squad.py`)
         `token_type_ids`: an optional torch.LongTensor of shape [batch_size, sequence_length] with the token
             types indices selected in [0, 1]. Type 0 corresponds to a `sentence A` and type 1 corresponds to

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
     """
@@ -180,6 +177,11 @@ class GPT2Config(object):
         """Serializes this instance to a JSON string."""
         return json.dumps(self.to_dict(), indent=2, sort_keys=True) + "\n"
 
+    def to_json_file(self, json_file_path):
+        """ Save this instance to a json file."""
+        with open(json_file_path, "w", encoding='utf-8') as writer:
+            writer.write(self.to_json_string())
+
 
 class Conv1D(nn.Module):
     def __init__(self, nf, nx):
@@ -216,7 +218,7 @@ class Attention(nn.Module):
             w = w / math.sqrt(v.size(-1))
         nd, ns = w.size(-2), w.size(-1)
         b = self.bias[:, :, ns-nd:ns, :ns]
-        w = w * b - 1e10 * (1 - b)
+        w = w * b - 1e4 * (1 - b)
 
         w = nn.Softmax(dim=-1)(w)
         return torch.matmul(w, v)
@@ -416,7 +418,7 @@ class GPT2PreTrainedModel(nn.Module):
         # Instantiate model.
         model = cls(config, *inputs, **kwargs)
         if state_dict is None and not from_tf:
-            state_dict = torch.load(resolved_archive_file, map_location='cpu' if not torch.cuda.is_available() else None)
+            state_dict = torch.load(resolved_archive_file, map_location='cpu')
         if from_tf:
             # Directly load from a TensorFlow checkpoint (stored as NumPy array)
             return load_tf_weights_in_gpt2(model, resolved_archive_file)

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)
@@ -225,6 +223,11 @@ class OpenAIGPTConfig(object):
         """Serializes this instance to a JSON string."""
         return json.dumps(self.to_dict(), indent=2, sort_keys=True) + "\n"
 
+    def to_json_file(self, json_file_path):
+        """ Save this instance to a json file."""
+        with open(json_file_path, "w", encoding='utf-8') as writer:
+            writer.write(self.to_json_string())
+
 
 class Conv1D(nn.Module):
     def __init__(self, nf, rf, nx):
@@ -473,7 +476,7 @@ class OpenAIGPTPreTrainedModel(nn.Module):
         # Instantiate model.
         model = cls(config, *inputs, **kwargs)
         if state_dict is None and not from_tf:
-            state_dict = torch.load(resolved_archive_file, map_location='cpu' if not torch.cuda.is_available() else None)
+            state_dict = torch.load(resolved_archive_file, map_location='cpu')
         if from_tf:
             # Directly load from a TensorFlow checkpoint (stored as NumPy array)
             return load_tf_weights_in_openai_gpt(model, resolved_archive_file)
@@ -605,14 +608,13 @@ class OpenAIGPTModel(OpenAIGPTPreTrainedModel):
             return
         # Update config
         self.config.n_special = num_special_tokens
-        # # Build new embeddings and initialize
+        # Build new embeddings and initialize all new embeddings (in particular the special tokens)
         old_embed = self.tokens_embed
         self.tokens_embed = nn.Embedding(self.config.total_tokens_embeddings, self.config.n_embd)
-        # Initialize all new embeddings (in particular the special tokens)
+        self.tokens_embed.to(old_embed.weight.device)
         self.init_weights(self.tokens_embed)
-        # Copy word and positional embeddings from the previous weights
-        self.tokens_embed.weight.data[: self.config.vocab_size, :] = old_embed.weight.data[: self.config.vocab_size, :]
-        self.tokens_embed.weight.data[-self.config.n_positions :, :] = old_embed.weight.data[-self.config.n_positions :, :]
+        # Copy word embeddings from the previous weights
+        self.tokens_embed.weight.data[:self.config.vocab_size, :] = old_embed.weight.data[:self.config.vocab_size, :]
 
     def forward(self, input_ids, position_ids=None, token_type_ids=None):
         if position_ids is None:
@@ -717,9 +719,8 @@ class OpenAIGPTLMHeadModel(OpenAIGPTPreTrainedModel):
         lm_logits = self.lm_head(hidden_states)
         if lm_labels is not None:
             # Shift so that tokens < n predict n
-            shift_logits = lm_logits[:, :-1].contiguous()
-            shift_labels = lm_labels[:, 1:].contiguous()
-
+            shift_logits = lm_logits[..., :-1, :].contiguous()
+            shift_labels = lm_labels[..., 1:].contiguous()
             # Flatten the tokens
             loss_fct = CrossEntropyLoss(ignore_index=-1)
             loss = loss_fct(shift_logits.view(-1, shift_logits.size(-1)),
@@ -809,11 +810,10 @@ class OpenAIGPTDoubleHeadsModel(OpenAIGPTPreTrainedModel):
         mc_logits = self.multiple_choice_head(hidden_states, mc_token_ids)
         losses = []
         if lm_labels is not None:
-            shift_logits = lm_logits[:, :-1].contiguous()
-            shift_labels = lm_labels[:, 1:].contiguous()
+            shift_logits = lm_logits[..., :-1, :].contiguous()
+            shift_labels = lm_labels[..., 1:].contiguous()
             loss_fct = CrossEntropyLoss(ignore_index=-1)
-            losses.append(loss_fct(shift_logits.view(-1,
-                          shift_logits.size(-1)), shift_labels.view(-1)))
+            losses.append(loss_fct(shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1)))
         if mc_labels is not None:
             loss_fct = CrossEntropyLoss()
             losses.append(loss_fct(mc_logits.view(-1, mc_logits.size(-1)), mc_labels.view(-1)))

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):
@@ -316,6 +315,11 @@ class TransfoXLConfig(object):
         """Serializes this instance to a JSON string."""
         return json.dumps(self.to_dict(), indent=2, sort_keys=True) + "\n"
 
+    def to_json_file(self, json_file_path):
+        """ Save this instance to a json file."""
+        with open(json_file_path, "w", encoding='utf-8') as writer:
+            writer.write(self.to_json_string())
+
 
 class PositionalEmbedding(nn.Module):
     def __init__(self, demb):
@@ -940,7 +944,7 @@ class TransfoXLPreTrainedModel(nn.Module):
         # Instantiate model.
         model = cls(config, *inputs, **kwargs)
         if state_dict is None and not from_tf:
-            state_dict = torch.load(resolved_archive_file, map_location='cpu' if not torch.cuda.is_available() else None)
+            state_dict = torch.load(resolved_archive_file, map_location='cpu')
         if from_tf:
             # Directly load from a TensorFlow checkpoint
             return load_tf_weights_in_transfo_xl(model, config, pretrained_model_name_or_path)

pytorch_pretrained_bert/tokenization.py

@@ -134,6 +134,21 @@ class BertTokenizer(object):
             tokens.append(self.ids_to_tokens[i])
         return tokens
 
+    def save_vocabulary(self, vocab_path):
+        """Save the tokenizer vocabulary to a directory or file."""
+        index = 0
+        if os.path.isdir(vocab_path):
+            vocab_file = os.path.join(vocab_path, VOCAB_NAME)
+        with open(vocab_file, "w", encoding="utf-8") as writer:
+            for token, token_index in sorted(self.vocab.items(), key=lambda kv: kv[1]):
+                if index != token_index:
+                    logger.warning("Saving vocabulary to {}: vocabulary indices are not consecutive."
+                                   " Please check that the vocabulary is not corrupted!".format(vocab_file))
+                    index = token_index
+                writer.write(token + u'\n')
+                index += 1
+        return vocab_file
+
     @classmethod
     def from_pretrained(cls, pretrained_model_name_or_path, cache_dir=None, *inputs, **kwargs):
         """

pytorch_pretrained_bert/tokenization_gpt2.py

@@ -16,6 +16,7 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
+import sys
 import json
 import logging
 import os
@@ -45,6 +46,7 @@ PRETRAINED_VOCAB_POSITIONAL_EMBEDDINGS_SIZE_MAP = {
 }
 VOCAB_NAME = 'vocab.json'
 MERGES_NAME = 'merges.txt'
+SPECIAL_TOKENS_NAME = 'special_tokens.txt'
 
 @lru_cache()
 def bytes_to_unicode():
@@ -57,6 +59,7 @@ def bytes_to_unicode():
     To avoid that, we want lookup tables between utf-8 bytes and unicode strings.
     And avoids mapping to whitespace/control characters the bpe code barfs on.
     """
+    _chr = unichr if sys.version_info[0] == 2 else chr
     bs = list(range(ord("!"), ord("~")+1))+list(range(ord("¡"), ord("¬")+1))+list(range(ord("®"), ord("ÿ")+1))
     cs = bs[:]
     n = 0
@@ -65,7 +68,7 @@ def bytes_to_unicode():
             bs.append(b)
             cs.append(2**8+n)
             n += 1
-    cs = [chr(n) for n in cs]
+    cs = [_chr(n) for n in cs]
     return dict(zip(bs, cs))
 
 def get_pairs(word):
@@ -94,9 +97,15 @@ class GPT2Tokenizer(object):
         if pretrained_model_name_or_path in PRETRAINED_VOCAB_ARCHIVE_MAP:
             vocab_file = PRETRAINED_VOCAB_ARCHIVE_MAP[pretrained_model_name_or_path]
             merges_file = PRETRAINED_MERGES_ARCHIVE_MAP[pretrained_model_name_or_path]
+            special_tokens_file = None
         else:
             vocab_file = os.path.join(pretrained_model_name_or_path, VOCAB_NAME)
             merges_file = os.path.join(pretrained_model_name_or_path, MERGES_NAME)
+            special_tokens_file = os.path.join(pretrained_model_name_or_path, SPECIAL_TOKENS_NAME)
+            if not os.path.exists(special_tokens_file):
+                special_tokens_file = None
+            else:
+                logger.info("loading special tokens file {}".format(special_tokens_file))
         # redirect to the cache, if necessary
         try:
             resolved_vocab_file = cached_path(vocab_file, cache_dir=cache_dir)
@@ -125,10 +134,14 @@ class GPT2Tokenizer(object):
             max_len = PRETRAINED_VOCAB_POSITIONAL_EMBEDDINGS_SIZE_MAP[pretrained_model_name_or_path]
             kwargs['max_len'] = min(kwargs.get('max_len', int(1e12)), max_len)
         # Instantiate tokenizer.
-        tokenizer = cls(resolved_vocab_file, resolved_merges_file, *inputs, **kwargs)
+        if special_tokens_file and 'special_tokens' not in kwargs:
+            special_tokens = open(special_tokens_file, encoding='utf-8').read().split('\n')[:-1]
+        else:
+            special_tokens = kwargs.pop('special_tokens', [])
+        tokenizer = cls(resolved_vocab_file, resolved_merges_file, special_tokens=special_tokens, *inputs, **kwargs)
         return tokenizer
 
-    def __init__(self, vocab_file, merges_file, errors='replace', max_len=None):
+    def __init__(self, vocab_file, merges_file, errors='replace', special_tokens=None, max_len=None):
         self.max_len = max_len if max_len is not None else int(1e12)
         self.encoder = json.load(open(vocab_file))
         self.decoder = {v:k for k,v in self.encoder.items()}
@@ -143,8 +156,25 @@ class GPT2Tokenizer(object):
         # Should haved added re.IGNORECASE so BPE merges can happen for capitalized versions of contractions
         self.pat = re.compile(r"""'s|'t|'re|'ve|'m|'ll|'d| ?\p{L}+| ?\p{N}+| ?[^\s\p{L}\p{N}]+|\s+(?!\S)|\s+""")
 
+        self.special_tokens = {}
+        self.special_tokens_decoder = {}
+        self.set_special_tokens(special_tokens)
+
     def __len__(self):
-        return len(self.encoder)
+        return len(self.encoder) + len(self.special_tokens)
+
+    def set_special_tokens(self, special_tokens):
+        """ Add a list of additional tokens to the encoder.
+            The additional tokens are indexed starting from the last index of the
+            current vocabulary in the order of the `special_tokens` list.
+        """
+        if not special_tokens:
+            self.special_tokens = {}
+            self.special_tokens_decoder = {}
+            return
+        self.special_tokens = dict((tok, len(self.encoder) + i) for i, tok in enumerate(special_tokens))
+        self.special_tokens_decoder = {v:k for k, v in self.special_tokens.items()}
+        logger.info("Special tokens {}".format(self.special_tokens))
 
     def bpe(self, token):
         if token in self.cache:
@@ -187,20 +217,85 @@ class GPT2Tokenizer(object):
         self.cache[token] = word
         return word
 
-    def encode(self, text):
+    def tokenize(self, text):
+        """ Tokenize a string. """
         bpe_tokens = []
         for token in re.findall(self.pat, text):
-            token = ''.join(self.byte_encoder[b] for b in token.encode('utf-8'))
-            bpe_tokens.extend(self.encoder[bpe_token] for bpe_token in self.bpe(token).split(' '))
-        if len(bpe_tokens) > self.max_len:
+            token = ''.join(self.byte_encoder[ord(b)] for b in token)
+            bpe_tokens.extend(bpe_token for bpe_token in self.bpe(token).split(' '))
+        return bpe_tokens
+
+    def convert_tokens_to_ids(self, tokens):
+        """ Converts a sequence of tokens into ids using the vocab. """
+        ids = []
+        if isinstance(tokens, str) or (sys.version_info[0] == 2 and isinstance(tokens, unicode)):
+            if tokens in self.special_tokens:
+                return self.special_tokens[tokens]
+            else:
+                return self.encoder.get(tokens, 0)
+        for token in tokens:
+            if token in self.special_tokens:
+                ids.append(self.special_tokens[token])
+            else:
+                ids.append(self.encoder.get(token, 0))
+        if len(ids) > self.max_len:
             logger.warning(
                 "Token indices sequence length is longer than the specified maximum "
-                " sequence length for this OpenAI GPT-2 model ({} > {}). Running this"
-                " sequence through the model will result in indexing errors".format(len(bpe_tokens), self.max_len)
+                " sequence length for this OpenAI GPT model ({} > {}). Running this"
+                " sequence through the model will result in indexing errors".format(len(ids), self.max_len)
             )
-        return bpe_tokens
+        return ids
+
+    def convert_ids_to_tokens(self, ids, skip_special_tokens=False):
+        """Converts a sequence of ids in BPE tokens using the vocab."""
+        tokens = []
+        for i in ids:
+            if i in self.special_tokens_decoder:
+                if not skip_special_tokens:
+                    tokens.append(self.special_tokens_decoder[i])
+            else:
+                tokens.append(self.decoder[i])
+        return tokens
+
+    def encode(self, text):
+        return self.convert_tokens_to_ids(self.tokenize(text))
 
     def decode(self, tokens):
         text = ''.join([self.decoder[token] for token in tokens])
         text = bytearray([self.byte_decoder[c] for c in text]).decode('utf-8', errors=self.errors)
         return text
+
+    def save_vocabulary(self, vocab_path):
+        """Save the tokenizer vocabulary and merge files to a directory."""
+        if not os.path.isdir(vocab_path):
+            logger.error("Vocabulary path ({}) should be a directory".format(vocab_path))
+            return
+        vocab_file = os.path.join(vocab_path, VOCAB_NAME)
+        merge_file = os.path.join(vocab_path, MERGES_NAME)
+        special_tokens_file = os.path.join(vocab_path, SPECIAL_TOKENS_NAME)
+
+        with open(vocab_file, 'w', encoding='utf-8') as f:
+            f.write(json.dumps(self.encoder, ensure_ascii=False))
+
+        index = 0
+        with open(merge_file, "w", encoding="utf-8") as writer:
+            writer.write(u'#version: 0.2\n')
+            for bpe_tokens, token_index in sorted(self.bpe_ranks.items(), key=lambda kv: kv[1]):
+                if index != token_index:
+                    logger.warning("Saving vocabulary to {}: BPE merge indices are not consecutive."
+                                   " Please check that the tokenizer is not corrupted!".format(merge_file))
+                    index = token_index
+                writer.write(' '.join(bpe_tokens) + u'\n')
+                index += 1
+
+        index = len(self.encoder)
+        with open(special_tokens_file, 'w', encoding='utf-8') as writer:
+            for token, token_index in sorted(self.special_tokens.items(), key=lambda kv: kv[1]):
+                if index != token_index:
+                    logger.warning("Saving special tokens vocabulary to {}: BPE indices are not consecutive."
+                                   " Please check that the tokenizer is not corrupted!".format(special_tokens_file))
+                    index = token_index
+                writer.write(token + u'\n')
+                index += 1
+
+        return vocab_file, merge_file, special_tokens_file

pytorch_pretrained_bert/tokenization_openai.py

@@ -41,6 +41,7 @@ PRETRAINED_VOCAB_POSITIONAL_EMBEDDINGS_SIZE_MAP = {
 }
 VOCAB_NAME = 'vocab.json'
 MERGES_NAME = 'merges.txt'
+SPECIAL_TOKENS_NAME = 'special_tokens.txt'
 
 def get_pairs(word):
     """
@@ -86,9 +87,15 @@ class OpenAIGPTTokenizer(object):
         if pretrained_model_name_or_path in PRETRAINED_VOCAB_ARCHIVE_MAP:
             vocab_file = PRETRAINED_VOCAB_ARCHIVE_MAP[pretrained_model_name_or_path]
             merges_file = PRETRAINED_MERGES_ARCHIVE_MAP[pretrained_model_name_or_path]
+            special_tokens_file = None
         else:
             vocab_file = os.path.join(pretrained_model_name_or_path, VOCAB_NAME)
             merges_file = os.path.join(pretrained_model_name_or_path, MERGES_NAME)
+            special_tokens_file = os.path.join(pretrained_model_name_or_path, SPECIAL_TOKENS_NAME)
+            if not os.path.exists(special_tokens_file):
+                special_tokens_file = None
+            else:
+                logger.info("loading special tokens file {}".format(special_tokens_file))
         # redirect to the cache, if necessary
         try:
             resolved_vocab_file = cached_path(vocab_file, cache_dir=cache_dir)
@@ -117,7 +124,11 @@ class OpenAIGPTTokenizer(object):
             max_len = PRETRAINED_VOCAB_POSITIONAL_EMBEDDINGS_SIZE_MAP[pretrained_model_name_or_path]
             kwargs['max_len'] = min(kwargs.get('max_len', int(1e12)), max_len)
         # Instantiate tokenizer.
-        tokenizer = cls(resolved_vocab_file, resolved_merges_file, *inputs, **kwargs)
+        if special_tokens_file and 'special_tokens' not in kwargs:
+            special_tokens = open(special_tokens_file, encoding='utf-8').read().split('\n')[:-1]
+        else:
+            special_tokens = kwargs.pop('special_tokens', [])
+        tokenizer = cls(resolved_vocab_file, resolved_merges_file, special_tokens=special_tokens, *inputs, **kwargs)
         return tokenizer
 
     def __init__(self, vocab_file, merges_file, special_tokens=None, max_len=None):
@@ -139,6 +150,8 @@ class OpenAIGPTTokenizer(object):
         merges = [tuple(merge.split()) for merge in merges]
         self.bpe_ranks = dict(zip(merges, range(len(merges))))
         self.cache = {}
+        self.special_tokens = {}
+        self.special_tokens_decoder = {}
         self.set_special_tokens(special_tokens)
 
     def __len__(self):
@@ -250,14 +263,51 @@ class OpenAIGPTTokenizer(object):
                 tokens.append(self.decoder[i])
         return tokens
 
-    def decode(self, ids, skip_special_tokens=False, clean_up_tokenization_spaces=False):
+    def encode(self, text):
+        return self.convert_tokens_to_ids(self.tokenize(text))
+
+    def decode(self, ids, skip_special_tokens=False, clean_up_tokenization_spaces=True):
         """Converts a sequence of ids in a string."""
         tokens = self.convert_ids_to_tokens(ids, skip_special_tokens=skip_special_tokens)
         out_string = ''.join(tokens).replace('</w>', ' ').strip()
         if clean_up_tokenization_spaces:
             out_string = out_string.replace('<unk>', '')
             out_string = out_string.replace(' .', '.').replace(' ?', '?').replace(' !', '!').replace(' ,', ',').replace(' ,', ','
-                    ).replace(" n't", "n't").replace(" 'm", "'m").replace(" 're", "'re").replace(" do not", " don't"
-                    ).replace(" 's", "'s").replace(" t ", "'t ").replace(" s ", "'s ").replace(" m ", "'m "
-                    ).replace(" 've", "'ve")
+                    ).replace(" ' ", "'").replace(" n't", "n't").replace(" 'm", "'m").replace(" do not", " don't"
+                    ).replace(" 's", "'s").replace(" 've", "'ve").replace(" 're", "'re")
         return out_string
+
+    def save_vocabulary(self, vocab_path):
+        """Save the tokenizer vocabulary and merge files to a directory."""
+        if not os.path.isdir(vocab_path):
+            logger.error("Vocabulary path ({}) should be a directory".format(vocab_path))
+            return
+        vocab_file = os.path.join(vocab_path, VOCAB_NAME)
+        merge_file = os.path.join(vocab_path, MERGES_NAME)
+        special_tokens_file = os.path.join(vocab_path, SPECIAL_TOKENS_NAME)
+
+        with open(vocab_file, 'w', encoding='utf-8') as f:
+            f.write(json.dumps(self.encoder, ensure_ascii=False))
+
+        index = 0
+        with open(merge_file, "w", encoding="utf-8") as writer:
+            writer.write(u'#version: 0.2\n')
+            for bpe_tokens, token_index in sorted(self.bpe_ranks.items(), key=lambda kv: kv[1]):
+                if index != token_index:
+                    logger.warning("Saving vocabulary to {}: BPE merge indices are not consecutive."
+                                   " Please check that the tokenizer is not corrupted!".format(merge_file))
+                    index = token_index
+                writer.write(' '.join(bpe_tokens) + u'\n')
+                index += 1
+
+        index = len(self.encoder)
+        with open(special_tokens_file, 'w', encoding='utf-8') as writer:
+            for token, token_index in sorted(self.special_tokens.items(), key=lambda kv: kv[1]):
+                if index != token_index:
+                    logger.warning("Saving special tokens vocabulary to {}: BPE indices are not consecutive."
+                                   " Please check that the tokenizer is not corrupted!".format(special_tokens_file))
+                    index = token_index
+                writer.write(token + u'\n')
+                index += 1
+
+        return vocab_file, merge_file, special_tokens_file

pytorch_pretrained_bert/tokenization_transfo_xl.py

@@ -63,7 +63,10 @@ class TransfoXLTokenizer(object):
         if pretrained_model_name_or_path in PRETRAINED_VOCAB_ARCHIVE_MAP:
             vocab_file = PRETRAINED_VOCAB_ARCHIVE_MAP[pretrained_model_name_or_path]
         else:
-            vocab_file = os.path.join(pretrained_model_name_or_path, VOCAB_NAME)
+            if os.path.isdir(pretrained_model_name_or_path):
+                vocab_file = os.path.join(pretrained_model_name_or_path, VOCAB_NAME)
+            else:
+                vocab_file = pretrained_model_name_or_path
         # redirect to the cache, if necessary
         try:
             resolved_vocab_file = cached_path(vocab_file, cache_dir=cache_dir)
@@ -141,6 +144,14 @@ class TransfoXLTokenizer(object):
         else:
             raise ValueError('No <unkown> token in vocabulary')
 
+    def save_vocabulary(self, vocab_path):
+        """Save the tokenizer vocabulary to a directory or file."""
+        index = 0
+        if os.path.isdir(vocab_path):
+            vocab_file = os.path.join(vocab_path, VOCAB_NAME)
+        torch.save(self.__dict__, vocab_file)
+        return vocab_file
+
     def build_vocab(self):
         if self.vocab_file:
             print('building vocab from {}'.format(self.vocab_file))
@@ -245,82 +256,24 @@ class TransfoXLTokenizer(object):
     def __len__(self):
         return len(self.idx2sym)
 
-    def _run_split_on_punc(self, text):
-        """Splits punctuation on a piece of text."""
-        if text in self.never_split:
-            return [text]
-        chars = list(text)
-        i = 0
-        start_new_word = True
-        output = []
-        while i < len(chars):
-            char = chars[i]
-            if _is_punctuation(char):
-                output.append([char])
-                start_new_word = True
-            else:
-                if start_new_word:
-                    output.append([])
-                start_new_word = False
-                output[-1].append(char)
-            i += 1
-
-        return ["".join(x) for x in output]
-
-    def _run_strip_accents(self, text):
-        """Strips accents from a piece of text."""
-        text = unicodedata.normalize("NFD", text)
-        output = []
-        for char in text:
-            cat = unicodedata.category(char)
-            if cat == "Mn":
-                continue
-            output.append(char)
-        return "".join(output)
-
-    def _clean_text(self, text):
-        """Performs invalid character removal and whitespace cleanup on text."""
-        output = []
-        for char in text:
-            cp = ord(char)
-            if cp == 0 or cp == 0xfffd or _is_control(char):
-                continue
-            if _is_whitespace(char):
-                output.append(" ")
-            else:
-                output.append(char)
-        return "".join(output)
-
-    def whitespace_tokenize(self, text):
-        """Runs basic whitespace cleaning and splitting on a piece of text."""
-        text = text.strip()
-        if not text:
-            return []
-        if self.delimiter == '':
-            tokens = text
-        else:
-            tokens = text.split(self.delimiter)
-        return tokens
-
     def tokenize(self, line, add_eos=False, add_double_eos=False):
-        line = self._clean_text(line)
         line = line.strip()
+        # convert to lower case
+        if self.lower_case:
+            line = line.lower()
 
-        symbols = self.whitespace_tokenize(line)
-
-        split_symbols = []
-        for symbol in symbols:
-            if self.lower_case and symbol not in self.never_split:
-                symbol = symbol.lower()
-                symbol = self._run_strip_accents(symbol)
-            split_symbols.extend(self._run_split_on_punc(symbol))
+        # empty delimiter '' will evaluate False
+        if self.delimiter == '':
+            symbols = line
+        else:
+            symbols = line.split(self.delimiter)
 
         if add_double_eos: # lm1b
-            return ['<S>'] + split_symbols + ['<S>']
+            return ['<S>'] + symbols + ['<S>']
         elif add_eos:
-            return split_symbols + ['<eos>']
+            return symbols + ['<eos>']
         else:
-            return split_symbols
+            return symbols
 
 
 class LMOrderedIterator(object):
@@ -631,42 +584,3 @@ def get_lm_corpus(datadir, dataset):
         torch.save(corpus, fn)
 
     return corpus
-
-def _is_whitespace(char):
-    """Checks whether `chars` is a whitespace character."""
-    # \t, \n, and \r are technically contorl characters but we treat them
-    # as whitespace since they are generally considered as such.
-    if char == " " or char == "\t" or char == "\n" or char == "\r":
-        return True
-    cat = unicodedata.category(char)
-    if cat == "Zs":
-        return True
-    return False
-
-
-def _is_control(char):
-    """Checks whether `chars` is a control character."""
-    # These are technically control characters but we count them as whitespace
-    # characters.
-    if char == "\t" or char == "\n" or char == "\r":
-        return False
-    cat = unicodedata.category(char)
-    if cat.startswith("C"):
-        return True
-    return False
-
-
-def _is_punctuation(char):
-    """Checks whether `chars` is a punctuation character."""
-    cp = ord(char)
-    # We treat all non-letter/number ASCII as punctuation.
-    # Characters such as "^", "$", and "`" are not in the Unicode
-    # Punctuation class but we treat them as punctuation anyways, for
-    # consistency.
-    if ((cp >= 33 and cp <= 47) or (cp >= 58 and cp <= 64) or
-            (cp >= 91 and cp <= 96) or (cp >= 123 and cp <= 126)):
-        return True
-    cat = unicodedata.category(char)
-    if cat.startswith("P"):
-        return True
-    return False