Sequence Protocol, assign item

[Torsten Mohr]

Hi,

thanks for that hint.  I already tried to get some hints from the sources
but at another place.

A) How it is done in Objects/listobject.c:

static int
list_ass_item(PyListObject *a, int i, PyObject *v)
{
        PyObject *old_value;
        if (i < 0 || i >= a->ob_size) {
                PyErr_SetString(PyExc_IndexError,
                                "list assignment index out of range");
                return -1;
        }
        if (v == NULL)
                return list_ass_slice(a, i, i+1, v);
        Py_INCREF(v);
        old_value = a->ob_item[i];
        a->ob_item[i] = v;
        Py_DECREF(old_value);
        return 0;
}

B) How i do it:

static int pytypeseq_ass_item(PyObject* s, int nr, PyObject* val) {
        int v;
        pytype_obj* self = (pytype_obj*)s;

        if(!PyArg_ParseTuple(val, "i", &v)) {
                return 0;
        }

        self->msg.d[nr] = v;
        /* if(nr > dlc && nr < 8) dlc = nr; */

        return 0;
}

In part A some INCREF/DECREF stuff is done, but i think i don't need
this as the PyObjects are only temporarily.

In the test script i use this:
#! /usr/bin/python

from pytype import *

m = PyType();
m.setContent(17, 22, 13);

print m[0], m[1], m[2];

m[0] = 12;

print m[0], m[1], m[2];


When i do it like this, i get:
C:\home\vc++\type\python>qwe.py
Exception exceptions.SystemError: 'new style getargs format but argument \
is not a tuple' in 'garbage collection' ignored

Fatal Python error: unexpected exception during garbage collection

#abnormal program termination


When i delete the line "m[0] = 12;" i do NOT get this error.


I don't really know what this message means, i think i don't correctly
handle the internal data structures somehow.

Has anybody got a hint for me?


Thanks,
Torsten.