string_center(PyStringObject *self, PyObject *args)
{
    Py_ssize_t marg, left;
    Py_ssize_t width;
    char fillchar = ' ';

    if (!PyArg_ParseTuple(args, "n|c:center", &width, &fillchar))
        return NULL;

    if (PyString_GET_SIZE(self) >= width && PyString_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    marg = width - PyString_GET_SIZE(self);
    left = marg / 2 + (marg & width & 1);

    return pad(self, left, marg - left, fillchar);
}
Unknown