Returning a lot of data from a c extension (SWIG,array, Numeric)

[Marcus Stojek]

Hi,

I have a c-extension that receives looong lists of doubles,
does some calculations and then returns those in another 
loong list. After some hard work (don't know much about c)
I got it running with SWIG and can use my module very 
comfortable now.

//typedef double d_list_out
%typemap(argout) (d_list_out *, int) {
    PyObject *o, *o2, *o3;
    PyObject *item;
    int      i;
    double   *vec =$1;
    int      size =$2;
//this is so s...l........o...........w
    o=PyList_New(0);//or better PyList_New(size)?
    for (i=0;i<size;i++) {
        item = PyFloat_FromDouble(vec[i]);
        PyList_Append(o,item);
    }
//.....................................
    if ((!$result) || ($result == Py_None)) {
        $result = o;
    } else {
        if (!PyTuple_Check($result)) {
            PyObject *o2 = $result;
            $result = PyTuple_New(1);
            PyTuple_SET_ITEM($result,0,o2);
        }
        o3 = PyTuple_New(1);
        PyTuple_SetItem(o3,0,o);
        o2 = $result;
        $result = PySequence_Concat(o2,o3);
        Py_DECREF(o2);
        Py_DECREF(o3);
    }

But what a shock! Returning my c-array into a Python list
takes almost as long as the calculations would have if done
in Python.

deja gave me a hint to use the array module to transform
'raw memory' into a list. But I have no idea how to this.

Or is the Numeric module what i need? Again I have no idea
how to use it in this context.

Thanks for any help.
marcus