Update model.py

src/models/model.py

@@ -127,3 +127,7 @@ class PLDataModule(LightningDataModule):
         )
 
     def train_dataloader(self):
+        """ training dataloader """
+        return DataLoader(
+            self.train_dataset, batch_size=self.batch_size, shuffle=True, num_workers=2
+        )