Looking for example of embedded Python

[Phil Austin]

chris_barker at my-deja.com writes:

> Hi,
> 
> I'm trying to persuade my co-workers that it would be extememly usefull
> to imbed Python in some of our apps. I'm looking for example
> applications wioth Python embedded. Ideally something fairly small with
> source code available.
> 

In addition to Demo/embed/demo.c, a nice example that tests Numpy
array classes using CXX-4.2 (http://CXX.sourceforge.net) has been
written by Paul Dubois.  It works for me using KCC under solaris and
linux, and should also compile with g++ 2.95.2. (I got segfaults
under linux until I  remember that the correct  linker  sequence
needed -Xlinker -export-dynamic,  e.g:

gcc  -Xlinker -export-dynamic demo.o -L/home/phil/lib/pythonmain/linux/lib/python1.5/config \
   -lpython1.5   -lieee -ldl  -lm  -o mydemo


Here's the output,  followed by the source:

<peacock ~/CXX/CXX-4.2> arraytest
Array facility test
[ 0.   0.5  1.   1.5  2.   2.5  3.   3.5  4.   4.5  5.   5.5]
Rank is 1
Species is 7
dimension(1) = 12
Pointers 125188, 1200b8, 125188
A list: [9.0, 4.0, 1.0]
toArray: [ 9.  4.  1.]
<type 'array'>
list+list: [ 18.   8.   2.]
add 2: [ 11.   6.   3.]
list[1]: 4.0
sorted: [ 1.  4.  9.]


/* Minimal main program -- everything is loaded from the library */

#include "Python.h"
#include <iostream>
#include "CXX_Array.h"
#include <algorithm>

using namespace Py;

extern "C" int Py_Main(int argc, char** argv);
extern "C" void Py_Initialize();
extern "C" void Py_Finalize();
//extern "C" void PyImport_ImportModule(char *name);

int
main(int argc, char** argv)
{
    PyObject *ptype;
    PyObject *pvalue;
    PyObject *ptrace;

	std::cout << "Array facility test" << std::endl;
	Py_Initialize();
	import_array();
	PyImport_ImportModule("Numeric");

    try {
        Array t(12);
        for(int i=0; i < t.length(); ++i) t[i] = Float(i / 2.0);
        std::cout << t << std::endl;
        std::cout << "Rank is " << t.rank() << std::endl;
        std::cout << "Species is " << t.species() << std::endl;
        std::cout << "dimension(1) = " << t.dimension(1) << std::endl;
        std::cout << "Pointers " << t.ptr() << ", " << (void *) t.to_C() << 
            ", " << t.as_contiguous().ptr() << std::endl;
        List w(3);
        w[0] = Float(9.0);
        w[1] = Float(4.0);
        w[2] = Float(1.0);
        Array from_list = toArray(w);
        std::cout << "A list: " << w << std::endl;
        std::cout << "toArray: " << from_list << std::endl;
        std::cout << from_list.type() << std::endl;
	//return Py_Main(argc, argv);
        std::cout << "list+list: " << from_list + from_list << std::endl;
        std::cout << "add 2: " << from_list + Int(2) << std::endl;
		std::cout << "list[1]: " << from_list[1] << std::endl;
		std::sort(from_list.begin(), from_list.end());
		std::cout << "sorted: " << from_list << std::endl;
    }
    catch(Exception&) {
        std::cout << "Test failed via Exception" << std::endl;
        PyErr_Fetch (&ptype, &pvalue, &ptrace);
        FromAPI p(pvalue);
        Object v(p);
        std::cout << v << std::endl;
    }

    Py_Finalize();
	return 0;
}