Python C API make member private-CodePudding

I'm making a python extension module using my C code and I've made a struct that I use to pass my C variables. I want some of those variables to be inaccessible from the python level. How can I do that?

    typedef struct {
        PyObject_HEAD
        std::string region;
        std::string stream;

        bool m_is_surface = false;
        bool m_is_stream = false;
    } PyType;

I want m_is_surface and m_is_stream to be inaccessible by the user. Only PyType's methods should access it. So the and user CAN'T do something like this:

import my_module

instance = my_module.PyType()
instance.m_is_surface = False # This should raise an error. Or preferably the user can't see this at all

I cannot just add private to the struct because python type members are created as a standalone function and is linked to the type later on, so I cannot access them inside the struct's methods. So if I say:


 int PyType_init(PyType *self, PyObject *args, PyObject *kwds)
    {
        static char *kwlist[] = {"thread", "region", "stream", NULL};
        PyObject *tmp;


        if (!PyArg_ParseTupleAndKeywords(args, kwds, "bs|s", kwlist,
                                        &self->thread, &self->region, &self->stream))
            return -1;
        
        return 0;
    }

It will raise an is private within this context error.

CodePudding user response：

You should do nothing. Unless you create an accessor property these attributes are already inaccessible from Python. Python cannot automatically see C/C struct members.