Embedding python and multiple separate scripts

[Stefan D]

Hi,

I'm trying to embed python into an chat bot I've made in c++. After
googling around and reading docs for almost a day I have a few
questions. First of all it seems like the best way to be able to run
separate scripts in different, isolated environments is to create a
sub-interpreter (by using Py_NewInterprete()) with an associated thread
for each script/file. Or is this wrong?

The big problem I have is when I want to call a python function. When
loading a script I use the following code:
PyEval_AcquireLock(); // get global lock so we can create a new interpreter
threadState = Py_NewInterpreter(); // create a new sub-interpreter and
get a pointer to the first thread
PyThreadState_Swap(threadState); // switch to our new thread state
appModule = PyImport_AddModule("hostapp"); // create a module for this
program
PyModule_AddIntConstant(appModule, "SEVENTEEN", 17); // set a test constant
FILE* fp = fopen(filename, "r"); // load the python script file
PyRun_SimpleFile(fp, filename);
fclose(fp);
PyEval_ReleaseThread(threadState); // set current thread state to NULL
and release global lock

When loading a script that contains:
import hostapp
print "test: ",hostapp.SEVENTEEN

it prints out "test: 17" nicely after the call to PyRun_SimpleFile(...).
So far so good, but the problem starts when I try to call a python
function from c++. Here's the code that isn't working:
PyEval_AcquireThread(threadState);
PyObject* func = PyDict_GetItemString(PyImport_GetModuleDict(),
"testfunc");
if(PyCallable_Check(func)) {
// never get this far
}
PyEval_ReleaseThread(threadState);

PyDict_GetItemString always return NULL for me, although I've defined
the function as:
def testfunc():
print "hi there"

in the python file. Running PyRun_SimpleString("testfunc()\n") just
after PyEval_AcquireThread() works like a charm though. Any ideas? I
kinda get the feeling that I don't get the dict from
PyImport_GetModuleDict() that I'm expecting.

Thanks in advance..
/Stefan