API class creation

[kman3048]

Hello,

as a relative newcomer to Python API programming I've got a problem:

To extend Python:
- there is an API C call to create a module
- there is also a API C call to create a method
- there is an API C call to create a Class instance

Now, I need to create a Class and fill it with Methods and Variables.
There are means to create (and attache) methods and variables.
However, I have not found how to create a Class within a Module. Or do
I have to use a low level API function to allocate an Object from Heap?

One possible solution I think is not very elegant:
- define a module and class within Python scripting
- use this object by creating Instances of this object via API

Is there no better way (however, I don't know if above works anyway).

Thanks,
Matt

[Peter Maas]

Re: API class creation

kman3048 schrieb:[color=blue]
> Now, I need to create a Class and fill it with Methods and Variables.
> There are means to create (and attache) methods and variables.
> However, I have not found how to create a Class within a Module. Or do[/color]

import aModule
c = aClassGenerator ()
setattr(aModule ,'c',c)
ci = aModule.c()

--
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E-mail 'cGV0ZXIubWFhc0 BtcGx1c3IuZGU=\ n'.decode('base 64')
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[Daniel Dittmar]

Re: API class creation

kman3048 wrote:[color=blue]
> Hello,
>
> as a relative newcomer to Python API programming I've got a problem:
>
> To extend Python:
> - there is an API C call to create a module
> - there is also a API C call to create a method
> - there is an API C call to create a Class instance
>
> Now, I need to create a Class and fill it with Methods and Variables.
> There are means to create (and attache) methods and variables.
> However, I have not found how to create a Class within a Module. Or do
> I have to use a low level API function to allocate an Object from Heap?[/color]

static PyMethodDef moduleMethods [] = {
...
};

statichere PyTypeObject MyClassType = {
PyObject_HEAD_I NIT (NULL)
...
};

initmymodule ()
{
PyObject* module;
PyObject* dict;

module = Py_InitModule4 ("mymodule", moduleMethods,
"doc string", NULL, PYTHON_API_VERS ION);
if (module == NULL) {
return;
}
dict = PyModule_GetDic t (module);
PyDict_SetItemS tring (dict, "MyClass"),
(PyObject*) &MyClassType ));
}

Daniel

[kman3048]

Re: API class creation


Thanks, that helped a lot.

Anybody who wants to attempt the same might find the
source code tree of Python i.e. file src/Modules/cdmodule.c
helpful.

--Matt


Daniel Dittmar wrote:[color=blue]
> kman3048 wrote:[color=green]
> > Hello,
> >
> > as a relative newcomer to Python API programming I've got a problem:
> >
> > To extend Python:
> > - there is an API C call to create a module
> > - there is also a API C call to create a method
> > - there is an API C call to create a Class instance
> >
> > Now, I need to create a Class and fill it with Methods and Variables.
> > There are means to create (and attache) methods and variables.
> > However, I have not found how to create a Class within a Module. Or do
> > I have to use a low level API function to allocate an Object from Heap?[/color]
>
> static PyMethodDef moduleMethods [] = {
> ...
> };
>
> statichere PyTypeObject MyClassType = {
> PyObject_HEAD_I NIT (NULL)
> ...
> };
>
> initmymodule ()
> {
> PyObject* module;
> PyObject* dict;
>
> module = Py_InitModule4 ("mymodule", moduleMethods,
> "doc string", NULL, PYTHON_API_VERS ION);
> if (module == NULL) {
> return;
> }
> dict = PyModule_GetDic t (module);
> PyDict_SetItemS tring (dict, "MyClass"),
> (PyObject*) &MyClassType ));
> }
>
> Daniel[/color]