Access to C functions from a python class using self ?

[Giorgi Lekishvili]

Hi!
I guess I should try this:
PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name)

See http://www.python.org/doc/current/api/object.html

On the other hand, my opinion is that, you'd better use either swig in a way
that make all stuff in C/C++ first and then wrap ot to Python, or consider
Pyrex:
http://www.cosc.canterbury.ac.nz/~greg/python/Pyrex/

christophe grimault wrote:

> Hi there,
>
> I've been looking to 'ext & emb python', swig, cxx, ... for quite some
> time now, and I still can't figure out how to do the kind of stuff
> explained below...
>
> I define a class in python, let's say this simple class, just for the
> purpose of discussion :
>
> class Vector:
>     def __init__(self, x1, x2, x3):
>         self.x1, self.x2, self.x3 = x1, x2, x3
>
>     def sum(self):
>         return self.x1 + self.x2 + self.x3
>
> Now, I find that sum is slow, and I want to speedup things by replacing
> sum by a call to C.
> Looking at the manual, I can write something like:
>
> static PyObject *sum( PyObject *self, PyObject *args )
>
> and  the manual tells me how to access elements passed in args, but does
> not tell how to access elements (in fact attributes) of self. How can I
> retrieve self.x1, self.x2, and self.x3 as defined in the python class
> from *self passed to the C function ?
>
> The goal for me is to create classes quickly in Python. These classes
> have, say, a constructor and 5 to 30 methods. The object itself is quite
> complex (lots of attributes of different types) and only one or two
> method need very high speed and thus, must call C.
>
> And i want to avoid passing all the attributes needed by those C calls
> by increasing the *args !
>
> Any help would be appreciated !
>
> Christophe