Function array_argsort

numpy/core/src/multiarray/methods.c:1479–1534

}

static PyObject *
array_argsort(PyArrayObject *self,
        PyObject *const *args, Py_ssize_t len_args, PyObject *kwnames)
{
    int axis = -1;
    NPY_SORTKIND sortkind = NPY_QUICKSORT;
    PyObject *order = NULL, *res;
    PyArray_Descr *newd, *saved=NULL;
    NPY_PREPARE_ARGPARSER;

    if (npy_parse_arguments("argsort", args, len_args, kwnames,
            "|axis", &PyArray_AxisConverter, &axis,
            "|kind", &PyArray_SortkindConverter, &sortkind,
            "|order", NULL, &order,
            NULL, NULL, NULL) < 0) {
        return NULL;
    }
    if (order == Py_None) {
        order = NULL;
    }
    if (order != NULL) {
        PyObject *new_name;
        PyObject *_numpy_internal;
        saved = PyArray_DESCR(self);
        if (!PyDataType_HASFIELDS(saved)) {
            PyErr_SetString(PyExc_ValueError, "Cannot specify "
                            "order when the array has no fields.");
            return NULL;
        }
        _numpy_internal = PyImport_ImportModule("numpy.core._internal");
        if (_numpy_internal == NULL) {
            return NULL;
        }
        new_name = PyObject_CallMethod(_numpy_internal, "_newnames",
                                       "OO", saved, order);
        Py_DECREF(_numpy_internal);
        if (new_name == NULL) {
            return NULL;
        }
        newd = PyArray_DescrNew(saved);
        if (newd == NULL) {
            Py_DECREF(new_name);
            return NULL;
        }
        Py_DECREF(newd->names);
        newd->names = new_name;
        ((PyArrayObject_fields *)self)->descr = newd;
    }

    res = PyArray_ArgSort(self, axis, sortkind);
    if (order != NULL) {
        Py_XDECREF(PyArray_DESCR(self));
        ((PyArrayObject_fields *)self)->descr = saved;
    }
    return PyArray_Return((PyArrayObject *)res);
}