Python, Swig, and callbacks

[unhappy_mage]

I'm writing a Python/Swig wrapper for some C code, and one of the things it does it take a callback function and use it to iterate over items. I want to properly wrap this: pass a Python callback function, and have some C code that translates the items that are iterated over into Python objects and then calls the Python function on these objects. I'm so close to being where I need to be, but I need one more layer of abstraction. I've already wrapped the struct itself, and I can create a new instance:

>>> myobj = mymodule.new(args)
>>> print myobj
<mymodule; proxy of <Swig Object of type 'my_c_class *' at 0x80a3938> >

All fine and good. This object has all the methods I've exposed. However, when I try the callback function thing, I have code like this:

	my_c_class the_child = my_c_class(m_parent, m_handle, child);
	resultobj = SWIG_NewPointerObj(SWIG_as_voidptr(&the_child), SWIGTYPE_p_mymodule, SWIG_POINTER_NEW |  0 );
	PyEval_CallObject(func, Py_BuildValue("(OO)", resultobj, realdata));

My callback function just prints its arguments for now:

def fn(x, data):
	print " Python arg is %s, and data is %s" % (x, data)
	print repr(x)

and when I run it I get output like this:

The Python says _18640408_p_mymodule, and data is None
<Swig Object of type 'my_c_class *' at 0x8046418>

and the methods I've defined are missing.

Looking at the output of swig, it looks like I'm constructing the C object properly, but not wrapping it in the Python needed to make everything work right. So the question is, how can I make the C code properly instantiate a Python object? What needs to go in my .i file to make this work?

 

[unhappy_mage]

I figured it out:

	resultobj = SWIG_NewPointerObj(SWIG_as_voidptr(&the_child), SWIGTYPE_p_mymodule, SWIG_POINTER_NEW |  0 );

This line is the problem. Take out "SWIG_POINTER_NEW | " and it works properly!