Hi I am trying to create a subclass of a python class, defined in python, in C++, but I am having some problems. It all boils down to a problem of finding the base class' type object and according to the PEP (253) I would also need to figure out the size of the base class instance structure, but I'm guessing that the latter can't be done in a way that would allow me to define a structure for my own type.
The following code is what I've tried, which is an adaptation of http://groups.google.com/group/comp.lang.python/msg/b32952c69182d366 /* import the module that holds the base class */ PyObject *code_module = PyImport_ImportModule("code"); if (!code_module) return; /* get a pointer to the base class */ PyObject *ic_class = PyMapping_GetItemString( PyModule_GetDict(code_module), "InteractiveConsole"); if (!ic_class) return; /* assign it as base class */ // The next line is the original code, but as far as I can understand // the docs for Py_BuildValue the code used is equivalent. I find it // to be clearer as well. // EmConType.tp_bases = Py_BuildValue("(O)", ic_class); Py_INCREF(ic_class); EmConType.tp_bases = ic_class; if (PyType_Ready(&EmConType) < 0) This breaks an assertion in the function classic_mro called by PyType_Ready however, specifically that on line 1000 of typeobject.c: assert(PyClass_Check(cls)). To get there you need to fail PyType_Check as well and indeed, at least in the debug build, cls.ob_type.tp_name is "dict". ic_class appears to be a "classobj" before the call to PyType_Ready. I would of course much rather have seen that it was a "type", but I'm not sufficiently well versed in the python guts to know if this is ok or not. If anyone could please lend me a clue, I'd be terribly happy about it. Thanks, Johan -- http://mail.python.org/mailman/listinfo/python-list
