PyObject *data - access to raw data?

[Thomas Gagne]

To learn python I decided to try creating a Python interface to my middleware
library, called isdio.  Before I get much passed the login/logout stuff
(though it is working) I'm curious:

The routines for sending and receiving data assume the programmer knows what
it is they want to send and what it is they are receiving.  Is there a way for
me to access PyObject data in a raw format, along with it's length, so that if
the programmer is passing a string of 20 characters I get a void * to the 20
characters AND can find out the length is 20 so I don't write too many bytes
in the network packet?

Is there a way I can coerce an arbitrary number of bytes in to PyObject
without knowing what kind of PyObject it is that's receiving it?  Say the
programmer knows they're getting a string, how can I return a string object if
all I know about in the receiving function is
a) the bytes I read
b) the number of bytes I read
c) a PyObject (I suppose) from PyArg_ParseTuple().

If I need to replace the value (c) contains, can I do this from within the C
function?

Theoretically, there will be a python module with python code wrapping the C
functions in isdio which may make it easier..

For the fun of it, I've attached my first module, isdio.c
-------------- next part --------------
#include "isdio.h"
#include "python1.5/Python.h"

static PyObject *login(PyObject *self, PyObject *args)
{
	char *hostname, *service;
	int priority;
	int socket;

	if (!PyArg_ParseTuple(args, "zzi", &hostname, &service, &priority)) {
		return NULL;
	}

	socket = isdLogin(hostname, service, priority);

	return Py_BuildValue("i", socket);
}


static PyObject *logout(PyObject *self, PyObject *args)
{
	int socket;

	if (!PyArg_ParseTuple(args, "i", &socket)) {
		return NULL;
	}

	isdLogout(socket);

	Py_INCREF(Py_None);
	return Py_None;
}

static PyMethodDef isdio_methods[] = {
	{ "login", login, 1, "int socket = isdLogin(string hostname, string servicename, int priority)" },
	{ "logout", logout, 1, "int result = isdLogout(int socket)" },
	{ NULL, NULL }
};

void initisdio(void)
{
	Py_InitModule("isdio", isdio_methods);
}