Fix encode plus

transformers/tokenization_utils.py

@@ -916,7 +916,7 @@ class PreTrainedTokenizer(object):
             return_tensors: (optional) can be set to 'tf' or 'pt' to return respectively TensorFlow tf.constant
                 or PyTorch torch.Tensor instead of a list of python integers.
             return_token_type_ids: (optional) Set to False to avoid returning token_type_ids (default True).
-            return_attention_mask: (optional) Set to False to avoir returning attention mask (default True)
+            return_attention_mask: (optional) Set to False to avoid returning attention mask (default True)
             return_overflowing_tokens: (optional) Set to True to return overflowing token information (default False).
             return_special_tokens_mask: (optional) Set to True to return special tokens mask information (default False).
 
@@ -961,24 +961,13 @@ class PreTrainedTokenizer(object):
         if add_special_tokens:
             sequence = self.build_inputs_with_special_tokens(ids, pair_ids)
             token_type_ids = self.create_token_type_ids_from_sequences(ids, pair_ids)
-            special_tokens_mask = self.get_special_tokens_mask(ids, pair_ids)
         else:
             sequence = ids + pair_ids if pair else ids
             token_type_ids = [0] * len(ids) + ([1] * len(pair_ids) if pair else [])
-            special_tokens_mask = [0] * (len(ids) + (len(pair_ids) if pair else 0))
+
         if return_special_tokens_mask:
             encoded_inputs["special_tokens_mask"] = self.get_special_tokens_mask(ids, pair_ids)
 
-        # Prepare inputs as tensors if asked
-        if return_tensors == 'tf' and is_tf_available():
-            sequence = tf.constant([sequence])
-            token_type_ids = tf.constant([token_type_ids])
-        elif return_tensors == 'pt' and is_torch_available():
-            sequence = torch.tensor([sequence])
-            token_type_ids = torch.tensor([token_type_ids])
-        elif return_tensors is not None:
-            logger.warning("Unable to convert output to tensors format {}, PyTorch or TensorFlow is not available.".format(return_tensors))
-
         encoded_inputs["input_ids"] = sequence
         if return_token_type_ids:
             encoded_inputs["token_type_ids"] = token_type_ids
@@ -1015,10 +1004,9 @@ class PreTrainedTokenizer(object):
                 if return_special_tokens_mask:
                     encoded_inputs["special_tokens_mask"] = encoded_inputs["special_tokens_mask"] + [1] * difference
                 encoded_inputs["input_ids"] = encoded_inputs["input_ids"] + [self.pad_token_id] * difference
-
             elif self.padding_side == 'left':
                 if return_attention_mask:
-                    encoded_inputs["attention_mask"] =  [0] * difference + [1] * len(encoded_inputs["input_ids"])
+                    encoded_inputs["attention_mask"] = [0] * difference + [1] * len(encoded_inputs["input_ids"])
                 if return_token_type_ids:
                     encoded_inputs["token_type_ids"] = [self.pad_token_type_id] * difference + encoded_inputs["token_type_ids"]
                 if return_special_tokens_mask:
@@ -1030,7 +1018,26 @@ class PreTrainedTokenizer(object):
             
         elif return_attention_mask:
             encoded_inputs["attention_mask"] = [1] * len(encoded_inputs["input_ids"])
-            
+
+        # Prepare inputs as tensors if asked
+        if return_tensors == 'tf' and is_tf_available():
+            encoded_inputs["input_ids"] = tf.constant([encoded_inputs["input_ids"]])
+            encoded_inputs["token_type_ids"] = tf.constant([encoded_inputs["token_type_ids"]])
+
+            if "attention_mask" in encoded_inputs:
+                encoded_inputs["attention_mask"] = tf.constant([encoded_inputs["attention_mask"]])
+
+        elif return_tensors == 'pt' and is_torch_available():
+            encoded_inputs["input_ids"] = torch.tensor([encoded_inputs["input_ids"]])
+            encoded_inputs["token_type_ids"] = torch.tensor([encoded_inputs["token_type_ids"]])
+
+            if "attention_mask" in encoded_inputs:
+                encoded_inputs["attention_mask"] = torch.tensor([encoded_inputs["attention_mask"]])
+        elif return_tensors is not None:
+            logger.warning(
+                "Unable to convert output to tensors format {}, PyTorch or TensorFlow is not available.".format(
+                    return_tensors))
+
         return encoded_inputs
 
     def truncate_sequences(self, ids, pair_ids=None, num_tokens_to_remove=0, truncation_strategy='longest_first', stride=0):