Python C/API - *arg,**kwds variable argumnents

[mdcb808@gmail.com]

I am writing a C extension with python 2.3.5 and need constructs
similar to python
func(*args, **kwds)
What's a neat way to do that?
I found pyrex has a __Pyx_GetStarAr gs -
is there something I'm missing from the regular C/API maybe using one
of the PyArg_Parse.. calls ?

Thanks,
M.

[Raymond L. Buvel]

Re: Python C/API - *arg,**kwds variable argumnents

mdcb808@gmail.c om wrote:[color=blue]
> I am writing a C extension with python 2.3.5 and need constructs
> similar to python
> func(*args, **kwds)
> What's a neat way to do that?
> I found pyrex has a __Pyx_GetStarAr gs -
> is there something I'm missing from the regular C/API maybe using one
> of the PyArg_Parse.. calls ?
>
> Thanks,
> M.
>[/color]

It looks like the PyArg_ParseTupl eAndKeywords API call is what you are
looking for. Documentation is

http://python.org/doc/2.4.2/ext/parseTupleAndKeywords.html

[mdcb808@gmail.com]

Re: Python C/API - *arg,**kwds variable argumnents

I saw that in 2.4, although it's not clear how I can make it work. the
argument char *format and char *keywords[] are fixed there. Does anyone
have a working example?
I'm just wondering if there are plans or already an API/C in python
core similar to __Pyx_GetStarAr gs. It seems like a very usefull and
common thing for extensions writer.
pyrex actually does a very neat job, looking at its output is really
instructive. How widespread is this solution? I started my extensions
long ago before realizing such solution existed, and rather stick to a
regular python API, understood this is what pyrex generates -

M.


Raymond L. Buvel wrote:[color=blue]
> mdcb808@gmail.c om wrote:[color=green]
> > I am writing a C extension with python 2.3.5 and need constructs
> > similar to python
> > func(*args, **kwds)
> > What's a neat way to do that?
> > I found pyrex has a __Pyx_GetStarAr gs -
> > is there something I'm missing from the regular C/API maybe using one
> > of the PyArg_Parse.. calls ?
> >
> > Thanks,
> > M.
> >[/color]
>
> It looks like the PyArg_ParseTupl eAndKeywords API call is what you are
> looking for. Documentation is
>
> http://python.org/doc/2.4.2/ext/pars...dKeywords.html[/color]

[mdcb808@gmail.com]

Re: Python C/API - *arg,**kwds variable argumnents

essentially I already use PyArg_ParseTupl eAndKeywords, but that seems
to emulate fixed arg list definitions like -
func (x,y,t=0,u=1)

[Fredrik Lundh]

Re: Python C/API - *arg,**kwds variable argumnents

mdcb808@gmail.c om wrote:
[color=blue]
> I am writing a C extension with python 2.3.5 and need constructs
> similar to python
> func(*args, **kwds)
> What's a neat way to do that?[/color]

static PyObject*
myfunc(PyObject * self, PyObject* args, PyObject* kw)
{
... args is a tuple, kw is a dictionary ...
}

static PyMethodDef _functions[] = {
{"myfunc", (PyCFunction) myfunc, METH_VARARGS|ME TH_KEYWORDS},
{NULL, NULL}
};

</F>

[Carsten Haese]

Re: Python C/API - *arg,**kwds variable argumnents

On Wed, 2005-12-14 at 12:00, mdcb808@gmail.c om wrote:[color=blue]
> essentially I already use PyArg_ParseTupl eAndKeywords, but that seems
> to emulate fixed arg list definitions like -
> func (x,y,t=0,u=1)[/color]

It's unclear what you are actually trying to accomplish. My guess is
that you want to implement a function/method that takes any number of
arbitrarily named keyword arguments. If that is the case, you can simply
use the dictionary that is passed to your C function as the third
argument.

Hope this helps,

Carsten.

[mdcb808@gmail.com]

Re: Python C/API - *arg,**kwds variable argumnents


thanks, I get it now.