Update src/knowledge_graph.py

src/knowledge_graph.py

@@ -360,9 +360,12 @@ class KnowledgeGraph:
         # Collect unique groups
         groups = set()
         for _, attrs in graph.nodes(data=True):
-            if "group" in attrs:
+            if "group" in attrs and attrs["group"] is not None:
                 groups.add(attrs["group"])
         
+        # 過濾並排序groups，確保沒有None值
+        sorted_groups = sorted([g for g in groups if g is not None])
+        
         # Generate HTML for legend
         legend_html = """
         <div id="graph-legend" style="position: absolute; top: 10px; right: 10px; background-color: rgba(255,255,255,0.8); 
@@ -372,7 +375,7 @@ class KnowledgeGraph:
         """
         
         # Add items for each group
-        for group in sorted(groups):
+        for group in sorted_groups:
             color = "#97c2fc"  # Default color
             if group == "property":
                 color = "#ffcc99"
@@ -831,9 +834,8 @@ class KnowledgeGraph:
                     "count": count,
                     "examples": examples
                 })
-        
-        # Sort by frequency
-        patterns.sort(key=lambda x: x["count"], reverse=True)
+                
+                patterns.sort(key=lambda x: x["count"], reverse=True)
         
         return patterns