From 853aa121a955ea359f2b5e9e6c0ade057ab76b4b Mon Sep 17 00:00:00 2001
From: Kevin Hu <kevinhu.sh@gmail.com>
Date: Wed, 14 Aug 2024 13:35:02 +0800
Subject: [PATCH] fix empty graph issue (#1939)

### What problem does this PR solve?


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
---
 graphrag/index.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/graphrag/index.py b/graphrag/index.py
index f2835cc7a..b4e93c551 100644
--- a/graphrag/index.py
+++ b/graphrag/index.py
@@ -85,7 +85,7 @@ def build_knowlege_graph_chunks(tenant_id: str, chunks: List[str], callback, ent
         graphs.append(_.result().output)
         callback(0.5 + 0.1*i/len(threads), f"Entities extraction progress ... {i+1}/{len(threads)}")
 
-    graph = reduce(graph_merge, graphs)
+    graph = reduce(graph_merge, graphs) if graphs else nx.Graph()
     er = EntityResolution(llm_bdl)
     graph = er(graph).output