Despite_Py_T_OBJECT being marked as deprecated indescrobject.h it is commonly used in the standard library.
LOAD_ATTR_SLOT de-optimizes if the stored value isNULL. If the stored value is notNULL, both_Py_T_OBJECT andPy_T_OBJECT_EX act the same, so we can reuseLOAD_ATTR_SLOT for_Py_T_OBJECT.

For storing attributes,_Py_T_OBJECT andPy_T_OBJECT_EX are exactly the same.

I don't know why_Py_T_OBJECT is deprecated, the semantics seem quite reasonable.

Linked PRs

• GH-111772: Specialize slot loads and stores for_Py_T_OBJECT #111773