Update search_utils.py

search_utils.py

@@ -151,10 +151,11 @@ class MetadataManager:
                 try:
                     # Load with explicit dtype for source column
                     self.loaded_shards[shard] = pd.read_parquet(
-                        shard_path, 
-                        columns=["title", "summary", "source", "authors"],
-                        dtype={'source': 'str'}
+                        shard_path,
+                        columns=["title", "summary", "source", "authors"]
                     )
+                    # Convert source to string type explicitly
+                    self.loaded_shards[shard]['source'] = self.loaded_shards[shard]['source'].astype(str)
                     # Convert source strings to lists
                     self.loaded_shards[shard]['source'] = self.loaded_shards[shard]['source'].apply(
                         lambda x: x.split("; ") if isinstance(x, str) else []