diff --git a/bootstrap/engines/engine.py b/bootstrap/engines/engine.py
index 86a74a4..88c63a8 100755
--- a/bootstrap/engines/engine.py
+++ b/bootstrap/engines/engine.py
@@ -201,7 +201,7 @@ def train_epoch(self, model, dataset, optimizer, epoch, mode='train'):
             for key, value in out.items():
                 if torch.is_tensor(value):
                     if value.numel() <= 1:
-                        value = value.item() # get number from a torch scalar
+                        value = value.item()  # get number from a torch scalar
                     else:
                         continue
                 if isinstance(value, (list, dict, tuple)):