Python C API - catch call to non-existent function

Question

I need to do some processing in the C backend during runtime. So what I want to do is, to define a C callback that'd get called each time there's a call to a non-existent python function.

For example:

// C code

PyObject* callback_func(PyObject* self, PyObject* args)
{

    // do stuff here
    return Py_BuildValue("");
}


# python code

print("Hello!")
call_xyz_func()
print("World!")

call_xyz_func is basically a non-existent python function. So it should call the C callback function and continue with the rest of the python code.