How to return new C++ objects in Cython?

Question

I suspect there is an easy answer to this, but I need some help getting started with Cython. I have an existing C++ code base which I want to expose to Python via Cython. For ea

Answer 1

You are returning a C++ object in a python function that is allowed to return python objects only:

def clone(self):
    return self.thisptr.clone()

Make it this:

cdef _Object clone(self) except *:
    return self.thisptr.clone()

But it depends on what you're trying to do, you probably want to return Object and not _Object, so I would modify it this way:

cdef class Object:
    cdef _Object thisobj
    cdef _Object *thisptr    

    def __cinit__(self, Object obj=None):
        if obj:
            self.thisobj = obj.thisobj.clone()
        self.thisptr = &self.thisobj

    def __dealloc__(self):
        pass

    def clone(self):
        return Object(self)