Function PyArray_DescrNewByteorder

numpy/core/src/multiarray/descriptor.c:3175–3262

NUMPY_API * * returns a copy of the PyArray_Descr structure with the byteorder * altered: * no arguments: The byteorder is swapped (in all subfields as well) * single argument: The byteorder is forced to the given state * (in all subfields as well) * * Valid states: ('big', '>') or ('little' or '<') * ('native', or '=') * * If a descr structure with | is encountered it's own * byte-

 * *** Leaves reference count of self unchanged --- does not DECREF self ***
 */
NPY_NO_EXPORT PyArray_Descr *
PyArray_DescrNewByteorder(PyArray_Descr *self, char newendian)
{
    PyArray_Descr *new;
    char endian;

    new = PyArray_DescrNew(self);
    if (new == NULL) {
        return NULL;
    }
    endian = new->byteorder;
    if (endian != NPY_IGNORE) {
        if (newendian == NPY_SWAP) {
            /* swap byteorder */
            if (PyArray_ISNBO(endian)) {
                endian = NPY_OPPBYTE;
            }
            else {
                endian = NPY_NATBYTE;
            }
            new->byteorder = endian;
        }
        else if (newendian != NPY_IGNORE) {
            new->byteorder = newendian;
        }
    }
    if (PyDataType_HASFIELDS(new)) {
        PyObject *newfields;
        PyObject *key, *value;
        PyObject *newvalue;
        PyObject *old;
        PyArray_Descr *newdescr;
        Py_ssize_t pos = 0;
        int len, i;

        newfields = PyDict_New();
        if (newfields == NULL) {
            Py_DECREF(new);
            return NULL;
        }
        /* make new dictionary with replaced PyArray_Descr Objects */
        while (PyDict_Next(self->fields, &pos, &key, &value)) {
            if (NPY_TITLE_KEY(key, value)) {
                continue;
            }
            if (!PyUnicode_Check(key) || !PyTuple_Check(value) ||
                ((len=PyTuple_GET_SIZE(value)) < 2)) {
                continue;
            }
            old = PyTuple_GET_ITEM(value, 0);
            if (!PyArray_DescrCheck(old)) {
                continue;
            }
            newdescr = PyArray_DescrNewByteorder(
                    (PyArray_Descr *)old, newendian);
            if (newdescr == NULL) {
                Py_DECREF(newfields); Py_DECREF(new);
                return NULL;