On Mar 22, 2014, at 12:50 PM, sagar masuti <sagar.masuti@gmail.com> wrote:

Is it possible to cast an int to a class type ?

Not safely.

How can I typecast the address passed from C to a class type in python so that i can access those class parameters or indirectly saying accessing the structure parameters?

I had to do something similar to support the passing of a C pointer (memory address) for my sysv_ipc module. Here’s how I did it --

PyObject * SharedMemory_attach(SharedMemory *self, PyObject *args) { PyObject *py_address = NULL; void *address = NULL; int flags = 0;

if (!PyArg_ParseTuple(args, "|Oi", &py_address, &flags))
    goto error_return;

if ((!py_address) || (py_address == Py_None))
    address = NULL;
else {
    if (PyLong_Check(py_address))
        address = PyLong_AsVoidPtr(py_address);
    else {
        PyErr_SetString(PyExc_TypeError, "address must be a long");
        goto error_return;
    }
}

// You should now be able to cast address as needed.

}

That code is pulled from memory.c in this module: http://semanchuk.com/philip/sysv_ipc/

I don’t think I invented that technique myself. I think someone on a mailing list (perhaps this one) gave me the idea.

Hope this helps Philip