[Python-Dev] class_init (original) (raw)

Thomas Heller thomas.heller@ion-tof.com
Fri, 16 Nov 2001 19:03:37 +0100

When implementing a metatype in C (a subtype of PyType_Type), aren't the tp_basicsize and tp_itemsize fields inherited?

This question is not covered in PEP 253...

I've attached the code below.

Thanks,

Thomas

#include <Python.h>

static PyMethodDef methods[] = { { NULL, NULL }, /* Sentinel */ };

PyTypeObject MyMeta_Type = { PyObject_HEAD_INIT(NULL) 0, /* ob_size / "mytype", / tp_name */ 0, /sizeof(PyTypeObject), / tp_basicsize / 0, / tp_itemsize / 0, / tp_dealloc / 0, / tp_print / 0, / tp_getattr / 0, / tp_setattr / 0, / tp_compare / 0, / tp_repr / 0, / tp_as_number / 0, / tp_as_sequence / 0, / tp_as_mapping / 0, / tp_hash / 0, / tp_call / 0, / tp_str / 0, / tp_getattro / 0, / tp_setattro / 0, / tp_as_buffer / Py_TPFLAGS_DEFAULT, / tp_flags / "a meta type", / tp_doc / 0, / tp_traverse / 0, / tp_clear / 0, / tp_richcompare / 0, / tp_weaklistoffset / 0, / tp_iter / 0, / tp_iternext / 0, / tp_methods / 0, / tp_members / 0, / tp_getset / 0, / tp_base / 0, / tp_dict / 0, / tp_descr_get / 0, / tp_descr_set / 0, / tp_dictoffset / 0, / tp_init / 0, / tp_alloc / 0, / tp_new / 0, / tp_free */ };

DL_EXPORT(void) initmetatype(void) { PyObject *m, *d;

MyMeta_Type.ob_type = &PyType_Type;
MyMeta_Type.tp_base = &PyType_Type;
MyMeta_Type.tp_basicsize = PyType_Type.tp_basicsize;
MyMeta_Type.tp_itemsize = PyType_Type.tp_itemsize;

if (PyType_Ready(&MyMeta_Type) < 0)
    return;

m = Py_InitModule3("metatype", methods, "provides a metatype");
d = PyModule_GetDict(m);

PyDict_SetItemString(d, "mytype", (PyObject *)&MyMeta_Type);

}