Map configs to models and tokenizers

src/transformers/configuration_auto.py

@@ -202,7 +202,7 @@ class AutoConfig:
                     return config_class.from_dict(config_dict, **kwargs)
 
         raise ValueError(
-            "Unrecognized model identifier in {}. Should have a `model_type` key in its config.json, or contain one of {}".format(
-                pretrained_model_name_or_path, ", ".join(CONFIG_MAPPING.keys())
-            )
+            "Unrecognized model in {}. "
+            "Should have a `model_type` key in its config.json, or contain one of the following strings "
+            "in its name: {}".format(pretrained_model_name_or_path, ", ".join(CONFIG_MAPPING.keys()))
         )

src/transformers/configuration_utils.py

@@ -273,7 +273,7 @@ class PretrainedConfig(object):
         return self.__dict__ == other.__dict__
 
     def __repr__(self):
-        return str(self.to_json_string())
+        return "{} {}".format(self.__class__.__name__, self.to_json_string())
 
     def to_dict(self):
         """Serializes this instance to a Python dictionary."""

src/transformers/tokenization_auto.py

@@ -16,6 +16,8 @@
 
 
 import logging
+from collections import OrderedDict
+from typing import Dict, Type
 
 from .configuration_auto import (
     AlbertConfig,
@@ -45,6 +47,7 @@ from .tokenization_openai import OpenAIGPTTokenizer
 from .tokenization_roberta import RobertaTokenizer
 from .tokenization_t5 import T5Tokenizer
 from .tokenization_transfo_xl import TransfoXLTokenizer
+from .tokenization_utils import PreTrainedTokenizer
 from .tokenization_xlm import XLMTokenizer
 from .tokenization_xlm_roberta import XLMRobertaTokenizer
 from .tokenization_xlnet import XLNetTokenizer
@@ -53,6 +56,25 @@ from .tokenization_xlnet import XLNetTokenizer
 logger = logging.getLogger(__name__)
 
 
+TOKENIZER_MAPPING: Dict[Type[PretrainedConfig], Type[PreTrainedTokenizer]] = OrderedDict(
+    [
+        (T5Config, T5Tokenizer),
+        (DistilBertConfig, DistilBertTokenizer),
+        (AlbertConfig, AlbertTokenizer),
+        (CamembertConfig, CamembertTokenizer),
+        (RobertaConfig, XLMRobertaTokenizer),
+        (XLMRobertaConfig, RobertaTokenizer),
+        (BertConfig, BertTokenizer),
+        (OpenAIGPTConfig, OpenAIGPTTokenizer),
+        (GPT2Config, GPT2Tokenizer),
+        (TransfoXLConfig, TransfoXLTokenizer),
+        (XLNetConfig, XLNetTokenizer),
+        (XLMConfig, XLMTokenizer),
+        (CTRLConfig, CTRLTokenizer),
+    ]
+)
+
+
 class AutoTokenizer(object):
     r""":class:`~transformers.AutoTokenizer` is a generic tokenizer class
         that will be instantiated as one of the tokenizer classes of the library
@@ -154,36 +176,13 @@ class AutoTokenizer(object):
         if "bert-base-japanese" in pretrained_model_name_or_path:
             return BertJapaneseTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
 
-        if isinstance(config, T5Config):
-            return T5Tokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, DistilBertConfig):
-            return DistilBertTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, AlbertConfig):
-            return AlbertTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, CamembertConfig):
-            return CamembertTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, XLMRobertaConfig):
-            return XLMRobertaTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, RobertaConfig):
-            return RobertaTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, BertConfig):
-            return BertTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, OpenAIGPTConfig):
-            return OpenAIGPTTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, GPT2Config):
-            return GPT2Tokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, TransfoXLConfig):
-            return TransfoXLTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, XLNetConfig):
-            return XLNetTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, XLMConfig):
-            return XLMTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
-        elif isinstance(config, CTRLConfig):
-            return CTRLTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
+        for config_class, tokenizer_class in TOKENIZER_MAPPING.items():
+            if isinstance(config, config_class):
+                return tokenizer_class.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
+
         raise ValueError(
-            "Unrecognized model identifier in {}. Should contains one of "
-            "'bert', 'openai-gpt', 'gpt2', 'transfo-xl', 'xlnet', "
-            "'xlm-roberta', 'xlm', 'roberta', 'distilbert,' 'camembert', 'ctrl', 'albert'".format(
-                pretrained_model_name_or_path
+            "Unrecognized configuration class {} to build an AutoTokenizer.\n"
+            "Model type should be one of {}.".format(
+                config.__class__, ", ".join(c.__name__ for c in MODEL_MAPPING.keys())
             )
         )

tests/test_configuration_auto.py

@@ -51,4 +51,4 @@ class AutoConfigTest(unittest.TestCase):
         # no key string should be included in a later key string (typical failure case)
         keys = list(CONFIG_MAPPING.keys())
         for i, key in enumerate(keys):
-            self.assertFalse(any(key in later_key for later_key in keys[i+1:]))
+            self.assertFalse(any(key in later_key for later_key in keys[i + 1 :]))