Call Python inside C++, how to get tuple output from python?

Question

I've got solver.py which has solver: tuple -> tuple function.

My usage of python in C++ looks like this:

    Py_Initialize();
    PyObject *name, *load_module, *func, *callfunc, *args;
    name = PyUnicode_FromString((char*)"solver");
    load_module = PyImport_Import(name);
    func = PyObject_GetAttrString(load_module, (char*)"solver");
    args = PyTuple_Pack(4,
        PyFloat_FromDouble(var1),
        PyFloat_FromDouble(var2),
        PyFloat_FromDouble(var3),
        PyFloat_FromDouble(var4)
    );
    callfunc = PyObject_CallObject(func, args);
    vector<double> solver_out = ???(callfunc);
    Py_Finalize();

I have a problem in getting a tuple from callfunc, i can't find the appropriate function which would convert the result of PyObject_CallObject to c++ vector. As I said before, python func returns tuple.

I'll be grateful for any help!

I've tried to find smth like "PyObject_AsTuple(callfunc)" but all didn't work.