From 28eb07b8fc3735f3a5918abafef95c2c0102cbb9 Mon Sep 17 00:00:00 2001
From: zdw <452202586@qq.com>
Date: Fri, 11 Apr 2025 11:48:27 +0800
Subject: [PATCH] fix: normalize rerank score to 0-1 range when only one
 document

---
 .../dify_plugin/interfaces/model/openai_compatible/rerank.py   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/python/dify_plugin/interfaces/model/openai_compatible/rerank.py b/python/dify_plugin/interfaces/model/openai_compatible/rerank.py
index 91b783f7..a31baa03 100644
--- a/python/dify_plugin/interfaces/model/openai_compatible/rerank.py
+++ b/python/dify_plugin/interfaces/model/openai_compatible/rerank.py
@@ -79,6 +79,9 @@ def _invoke(
             scores = [result["relevance_score"] for result in results["results"]]
 
             # Min-Max Normalization: Normalize scores to 0 ~ 1.0 range
+            if len(scores) == 1:
+                scores.append(0)
+                
             min_score = min(scores)
             max_score = max(scores)
             score_range = max_score - min_score if max_score != min_score else 1.0  # Avoid division by zero