Update app.py

app.py

@@ -130,7 +130,7 @@ def get_semantic_profile(word: str, lang: str = 'en', selected_relations: List[s
         return
 
     # Set default relations if none are selected
-    if not selected_relations:
+    if selected_relations is None or len(selected_relations) == 0:
         selected_relations = [
             "IsA", "RelatedTo", "PartOf", "HasA", "UsedFor", 
             "CapableOf", "Synonym", "Antonym"