[dpo] fix import (#5364)

Jintao-Huang · Jintao-Huang · commit 430071c8cf1a · 2025-08-14T15:31:09.000+08:00
diff --git a/swift/trainers/rlhf_trainer/dpo_trainer.py b/swift/trainers/rlhf_trainer/dpo_trainer.py
@@ -1,4 +1,5 @@
 # Copyright (c) Alibaba, Inc. and its affiliates.
+import warnings
 from typing import Dict, List, Optional, Tuple, Union
 
 import torch

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`# Copyright (c) Alibaba, Inc. and its affiliates.`
	`2`	`+import warnings`
`2`	`3`	`from typing import Dict, List, Optional, Tuple, Union`
`3`	`4`
`4`	`5`	`import torch`