Hello everyone,

Boy I feel sheepish, but I think I’ve found my problem.  In my PyTypeObject I had set tp_basicsize to sizeof(C++_ClassName) instead of the sizeof(Python_struct) where Python_struct is my

“typedef struct { PyObject_HEAD ...”  that wraps the C++ object.  The code I posted below seems to work just fine now.

Beau

From: Beau Sapach [mailto:beau.sapach@ualberta.ca]
Sent: Tuesday, November 07, 2006 3:47 PM
To: 'Development of Python/C++ integration'
Subject: Insert instance..... again

Hello everyone,

I know it seems like I’m beating a dead horse here, but I’m not having much luck in understanding the “proper” way to use some of the C API functions.  I want to insert an instance of one of my own objects into the python environment, here’s what I’ve got so far.

//get the main module

PyObject * pMainModule = PyImport_ImportModule("__main__");

//insert MyType into the main module     

Py_INCREF(MyType);

PyModule_AddObject(pMainModule,"MyObject",(PyObject*)&MyType);

//create an instance of mytype

PyObject * MyInstance = MakeMyObject();

//get the main module’s dictionary

PyObject * pMainDict = PyModule_GetDict(pMainModule);

//insert my instance into the dictionary under the name ‘testobject’

PyDict_SetItemString(pMainDict,"testobject",MyInstance);

//run a script that calls some function of my ‘testobject’ instance

PyRun_SimpleString("testobject.function()\n");

My object implements only a constructor, destructor and one function of its own. The above code crashes somewhere in the python DLL but appears to be trying to access something that’s un-initialized.  Is there something I’m doing wrong?  The above code works fine when I insert a PyObject integer created using PyInt_FromLong(). Minus of course the unnecessary PyModule_AddObject().  What’s different about my object?  Is there some functionality missing?  Should I be implementing some of the other functions in the PyTypeObject?  Any help would be appreciated!

Beau