start to add bert_fine_tuning_token_classification task

tasks.py

@@ -258,6 +258,33 @@ def load_dataset(self, split, **kwargs):
         print('| loading finished')
 
 
+class BertFineTuningTask(Task):
+    def __init__(self, dictionary):
+        super(BertFineTuningTask, self).__init__(args)
+        self.dictionary = dictionary
+
+    @classmethod
+    def setup_task(cls, args, **kwargs):
+        """Setup the task (e.g., load dictionaries).
+        Args:
+            args (argparse.Namespace): parsed command-line arguments
+        """
+        dictionary = cls.load_dictionary(cls, args.dict)
+
+        return cls(args, dictionary)
+
+    def build_model(self, args):
+        if args.task == 'BertForTokenClassification':
+            from bert_modeling import BertForPreTraining, BertConfig
+            config = BertConfig.from_json_file(args.config_file)
+            # mention detection, num_label is by default 3
+            num_label = args.num_label if hasattr(args, 'num_label') else 3
+            model = BertForTokenClassification(config, num_label)
+        else:
+            raise ValueError('Unknown fine_tunning task!')
+        return model
+
+
 class MNISTTask(Task):
     def __init__(self, args):
         super(MNISTTask, self).__init__(args)