[Trainer] changed the invalid index of a 0-dim tensor (data[0] to item())

bob/learn/pytorch/trainers/CNNTrainer.py

@@ -169,8 +169,8 @@ class CNNTrainer(object):
           optimizer.step()
 
           end = time.time()
-          logger.info("[{}/{}][{}/{}] => Loss = {} (time spent: {})".format(epoch, n_epochs, i, len(dataloader), loss.data[0], (end-start)))
-          losses.append(loss.data[0])
+          logger.info("[{}/{}][{}/{}] => Loss = {} (time spent: {})".format(epoch, n_epochs, i, len(dataloader), loss.item(), (end-start)))
+          losses.append(loss.item())
       
       # do stuff - like saving models
       logger.info("EPOCH {} DONE")