extending: new type instance

[BranoZ]

I'm writing my own (list-like) type in C. It is implementing
a Sequence Protocol. In 'sq_slice' method I would like to return
a new instance of my class/type.

How do I create (and initialize) an instance of a given
PyTypeObject MyType ?

I have tried to provide (PyObject *)&MyType as 'class' argument to:

PyInstance_New(PyObject *class, PyObject *arg, PyObject *kw)

It failed the PyClass_Check.

I have also found a couple of PyObject_New functions which accept
PyTypeObject as an argument. They look very low-level and obviously
don't call __init__. Should I do it myself manualy ?

BranoZ

 

[Michael Hudson]

I'm writing my own (list-like) type in C. It is implementing
a Sequence Protocol. In 'sq_slice' method I would like to return
a new instance of my class/type.

How do I create (and initialize) an instance of a given
PyTypeObject MyType ?

I have tried to provide (PyObject *)&MyType as 'class' argument to:

PyInstance_New(PyObject *class, PyObject *arg, PyObject *kw)

It failed the PyClass_Check.

I have also found a couple of PyObject_New functions which accept
PyTypeObject as an argument. They look very low-level and obviously
don't call __init__. Should I do it myself manualy ?

PyObject_New is the usual way, although there are others --
MyType.tp_new, PyObject_Call ...

Cheers,
mwh

 

[BranoZ]

PyObject_New is the usual way, although there are others --

Thanks for an answer !

MyType.tp_new, PyObject_Call ...

Does this mean, that I can call my newly defined
MyType_new, MyType_init directly ??

I was afraid that Python might do some pretty important
housekeeping stuff around them.

BranoZ