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]

"BranoZ" <za********@gma il.com> writes:

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

--
81. In computing, turning the obvious into the useful is a living
definition of the word "frustratio n".
-- Alan Perlis, http://www.cs.yale.edu/homes/perlis-alan/quotes.html

[BranoZ]

Michael Hudson wrote:

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