diff --git a/fastNLP/core/dataloaders/torch_dataloader/fdl.py b/fastNLP/core/dataloaders/torch_dataloader/fdl.py
index 09fa2ff6..1ee33c66 100644
--- a/fastNLP/core/dataloaders/torch_dataloader/fdl.py
+++ b/fastNLP/core/dataloaders/torch_dataloader/fdl.py
@@ -64,7 +64,7 @@ class TorchDataLoader(DataLoader):
     """
 
     def __init__(self, dataset, batch_size: int = 16,
-                 shuffle: bool = False, sampler = None, batch_sampler = None,
+                 shuffle: bool = False, sampler=None, batch_sampler=None,
                  num_workers: int = 0, collate_fn: Union[Callable, str, None] = 'auto',
                  pin_memory: bool = False, drop_last: bool = False,
                  timeout: float = 0, worker_init_fn: Optional[Callable] = None,