revert `_fields` of `Row`

diff --git a/lib/sqlalchemy/engine/row.py b/lib/sqlalchemy/engine/row.py
index 6a834a898579618fe55ac098c48238d4a4118799..0744569f831cdc0a6f49468fc52730a00778ef3d 100644 (file)
--- a/lib/sqlalchemy/engine/row.py
+++ b/lib/sqlalchemy/engine/row.py
@@ -263,7 +263,7 @@ class Row(BaseRow, _RowBase[Unpack[_Ts]], Generic[Unpack[_Ts]]):
             :attr:`.Row._mapping`
 
         """
-        return tuple(k for k in self._parent.keys if k is not None)
+        return tuple([k for k in self._parent.keys if k is not None])
 
     def _asdict(self) -> Dict[str, Any]:
         """Return a new dict which maps field names to their corresponding