#include <boost/python.hpp>
using namespace boost::python;

struct World {
    void set(std::string msg) { this->msg = msg; }
    std::string greet() { return msg; }

    void run() {

        handle<> main_module(borrowed( PyImport_AddModule("__main__") ));

        handle<> main_namespace(borrowed( PyModule_GetDict(main_module.get()) ));

        (handle<>( PyRun_String("hello = file('hello.txt', 'w')\n"
                                "hello.write('Hello world!')\n"
                                "hello.close()", Py_file_input,
                                main_namespace.get(), main_namespace.get()) ));

    }

private:
    std::string msg;
};

BOOST_PYTHON_MODULE(hello) {
    class_<World>("World")
        .def("greet", &World::greet)
        .def("set",   &World::set)
        .def("run",   &World::run)
    ;
}