Trainer.train should return the best checkpoint path. It returns None. (

#265)

This merge request fix this.

Co-authored-by: Benjamin Clavié <ben@clavie.eu>

ragatouille/models/colbert.py

@@ -451,6 +451,7 @@ def train(self, data_dir, training_config: ColBERTConfig):
             )
 
             trainer.train(checkpoint=self.checkpoint)
+            return trainer.best_checkpoint_path()
 
     def _colbert_score(self, Q, D_padded, D_mask):
         if ColBERTConfig().total_visible_gpus > 0: