Update utils.py (#21105)

backend/open_webui/retrieval/vector/utils.py

@@ -4,6 +4,7 @@ KEYS_TO_EXCLUDE = ["content", "pages", "tables", "paragraphs", "sections", "figu
 
 
 def filter_metadata(metadata: dict[str, any]) -> dict[str, any]:
+    # Removes large/redundant fields from metadata dict.
     metadata = {
         key: value for key, value in metadata.items() if key not in KEYS_TO_EXCLUDE
     }
@@ -13,16 +14,15 @@ def filter_metadata(metadata: dict[str, any]) -> dict[str, any]:
 def process_metadata(
     metadata: dict[str, any],
 ) -> dict[str, any]:
+    # Removes large fields and converts non-serializable types (datetime, list, dict) to strings.
+    result = {}
     for key, value in metadata.items():
-        # Remove large fields
+        # Skip large fields
         if key in KEYS_TO_EXCLUDE:
-            del metadata[key]
-
+            continue
         # Convert non-serializable fields to strings
-        if (
-            isinstance(value, datetime)
-            or isinstance(value, list)
-            or isinstance(value, dict)
-        ):
-            metadata[key] = str(value)
-    return metadata
+        if isinstance(value, (datetime, list, dict)):
+            result[key] = str(value)
+        else:
+            result[key] = value
+    return result