Re: [capi-sig] Beginner Question PyObject* to int

Nov. 12, 2008 · *self, PyObject*

      On 12/11/2008, at 1:55 AM, Philipp Heuser wrote:
...
Hi all,
I am just starting to use the C API for Python. What I want to do is

to use an external funtion availabele in C and therfore I want to

'convert' a list of floats from Python to an array of floats in C

which I can forward to the external function. So first step is tp

parse a list to C and let the C code print the variables! The

obviously too simplistic approach is below... When I call this

function from python, e.g. cpp([1,2,3]) the output is:
25180552
25180540
25180528
Could you be so kind to help me here to get started with using C-
functions from Python? Where is the error?
Thank you very much and kind regards,
Philipp
static PyObject *
cpp_foo(PyObject *self, PyObject* args)
{
PyObject* obj;
PyObject* seq;
int i, len;
if(!PyArg_ParseTuple(args, "O", &obj))
return NULL;
seq = PySequence_Fast(obj, "expected a sequence");
len = PySequence_Size(obj);
PyObject* item;
int a;
for (i=0; i<len; i++)
{
item=PySequence_Fast_GET_ITEM(seq, i);
a=item;  // ?????????????????????????????????????????
Perhaps something like:
 long a;
 a = PyInt_AsLong(item);
 if (a == -1 && PyErr_Occurred())
     return NULL; /* error */
 printf("%i\n", a);
Cheers,
Chris Miles