> *My* question would be (maybe this is what MAL meant): > why aren't the created types subclasses of PyTupleType? How would you inherit from PyTupleType in C? E.g. by doing struct PyStatType{ PyTupleType foo; PyObject *additional_field; }; That reads well, but it is wrong: PyTupleType ends in a flexible array member, so it cannot be used as the member of another struct. Regards, Martin