Clean up a little bit

examples/run_classifier.py

@@ -736,9 +736,28 @@ def main():
 
     tokenizer = BertTokenizer.from_pretrained(args.bert_model, do_lower_case=args.do_lower_case)
 
-    train_examples = None
-    num_train_optimization_steps = None
+    # Prepare model
+    cache_dir = args.cache_dir if args.cache_dir else os.path.join(str(PYTORCH_PRETRAINED_BERT_CACHE), 'distributed_{}'.format(args.local_rank))
+    model = BertForSequenceClassification.from_pretrained(args.bert_model,
+              cache_dir=cache_dir,
+              num_labels=num_labels)
+    if args.fp16:
+        model.half()
+    model.to(device)
+    if args.local_rank != -1:
+        try:
+            from apex.parallel import DistributedDataParallel as DDP
+        except ImportError:
+            raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use distributed and fp16 training.")
+
+        model = DDP(model)
+    elif n_gpu > 1:
+        model = torch.nn.DataParallel(model)
+
     if args.do_train:
+
+        # Prepare data loader
+
         train_examples = processor.get_train_examples(args.data_dir)
         train_features = convert_examples_to_features(
             train_examples, label_list, args.max_seq_length, tokenizer, output_mode)
@@ -762,26 +781,8 @@ def main():
         if args.local_rank != -1:
             num_train_optimization_steps = num_train_optimization_steps // torch.distributed.get_world_size()
 
-    # Prepare model
-    cache_dir = args.cache_dir if args.cache_dir else os.path.join(str(PYTORCH_PRETRAINED_BERT_CACHE), 'distributed_{}'.format(args.local_rank))
-    model = BertForSequenceClassification.from_pretrained(args.bert_model,
-              cache_dir=cache_dir,
-              num_labels=num_labels)
-    if args.fp16:
-        model.half()
-    model.to(device)
-    if args.local_rank != -1:
-        try:
-            from apex.parallel import DistributedDataParallel as DDP
-        except ImportError:
-            raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use distributed and fp16 training.")
+        # Prepare optimizer
 
-        model = DDP(model)
-    elif n_gpu > 1:
-        model = torch.nn.DataParallel(model)
-
-    # Prepare optimizer
-    if args.do_train:
         param_optimizer = list(model.named_parameters())
         no_decay = ['bias', 'LayerNorm.bias', 'LayerNorm.weight']
         optimizer_grouped_parameters = [
@@ -812,10 +813,10 @@ def main():
                                  warmup=args.warmup_proportion,
                                  t_total=num_train_optimization_steps)
 
-    global_step = 0
-    nb_tr_steps = 0
-    tr_loss = 0
-    if args.do_train:
+        global_step = 0
+        nb_tr_steps = 0
+        tr_loss = 0
+
         logger.info("***** Running training *****")
         logger.info("  Num examples = %d", len(train_examples))
         logger.info("  Batch size = %d", args.train_batch_size)