Fix #6092 (#6093)

* Fix #6092

* Format

src/transformers/data/data_collator.py

@@ -5,6 +5,7 @@
 from torch.nn.utils.rnn import pad_sequence
 
 from ..tokenization_utils import PreTrainedTokenizer
+from ..tokenization_utils_base import BatchEncoding
 
 
 InputDataClass = NewType("InputDataClass", Any)
@@ -33,7 +34,7 @@ def default_data_collator(features: List[InputDataClass]) -> Dict[str, torch.Ten
     # have the same attributes.
     # So we will look at the first element as a proxy for what attributes exist
     # on the whole batch.
-    if not isinstance(features[0], dict):
+    if not isinstance(features[0], (dict, BatchEncoding)):
         features = [vars(f) for f in features]
 
     first = features[0]
@@ -78,7 +79,7 @@ class DataCollatorForLanguageModeling:
     mlm_probability: float = 0.15
 
     def __call__(self, examples: List[Union[torch.Tensor, Dict[str, torch.Tensor]]]) -> Dict[str, torch.Tensor]:
-        if isinstance(examples[0], dict):
+        if isinstance(examples[0], (dict, BatchEncoding)):
             examples = [e["input_ids"] for e in examples]
         batch = self._tensorize_batch(examples)
         if self.mlm:
@@ -151,7 +152,7 @@ class DataCollatorForPermutationLanguageModeling:
     max_span_length: int = 5  # maximum length of a span of masked tokens
 
     def __call__(self, examples: List[Union[torch.Tensor, Dict[str, torch.Tensor]]]) -> Dict[str, torch.Tensor]:
-        if isinstance(examples[0], dict):
+        if isinstance(examples[0], (dict, BatchEncoding)):
             examples = [e["input_ids"] for e in examples]
         batch = self._tensorize_batch(examples)
         inputs, perm_mask, target_mapping, labels = self.mask_tokens(batch)