update return type

src/diary_cover_similarity.py

@@ -68,7 +68,7 @@ def save_faiss_index(load_file, save_path):
         ids_np = np.array(ids).astype("int")
         features_np = np.array(features).astype("float32")
         index = faiss.IndexHNSWFlat(128, 32)
-        print("trained: " + index.is_trained)
+        print("trained: " + str(index.is_trained))
         index2 = faiss.IndexIDMap(index)
         index2.add_with_ids(features_np, ids_np)
         faiss.write_index(index2, save_path)