return a ctypes object to C

[Arnaud Loonstra]

Hi all,

I'm trying to wrap my head around the ctypes API. I have a C structure I 
wish to create in Python and then return from python to C.

So a python method is called from C and needs to return an object which 
we then process in C again.

I have a binding to access and create the C methods and structures so in 
Python I can call the Zmsg() constructor. I now need to return this.

My python test method is simply:

def actor_test( *args, **kwargs):
     print("test")
     msg = Zmsg()
     frame = Zframe(b"Hello", 5)
     msg.prepend(frame)
     return msg

the method is called from C as follows:

PyObject *pReturn = PyObject_CallObject(pFunc, NULL);

This correctly calls the method. However the returned object is of 
course a PyObject*. The debugger says it's

"<czmq._czmq_ctypes.Zmsg object at 0x7ffff5f18e50>"	PyObject
			[class]	"<class 'czmq._czmq_ctypes.Zmsg'>"	
			[super class]	"<class 'object'>"	
			[meta type]	"<class 'type'>"	
			ob_refcnt	1	Py_ssize_t

However how I can I get it back to the original C type (zmsg_t *)

Any help really appreciated.

Rg,

Arnaud