Merge pull request #789 from alexta69/copilot/fix-32a91bc7-90af-4cfd-a3e1-d04a36659489

Fix AttributeError when serializing objects without __dict__ attribute

app/main.py

@@ -115,10 +115,18 @@ config = Config()
 
 class ObjectSerializer(json.JSONEncoder):
     def default(self, obj):
-        if isinstance(obj, object):
+        # First try to use __dict__ for custom objects
+        if hasattr(obj, '__dict__'):
             return obj.__dict__
-        else:
-            return json.JSONEncoder.default(self, obj)
+        # Convert iterables (generators, dict_items, etc.) to lists
+        # Exclude strings and bytes which are also iterable
+        elif hasattr(obj, '__iter__') and not isinstance(obj, (str, bytes)):
+            try:
+                return list(obj)
+            except:
+                pass
+        # Fall back to default behavior
+        return json.JSONEncoder.default(self, obj)
 
 serializer = ObjectSerializer()
 app = web.Application()