Function npyiter_seq_item

numpy/core/src/multiarray/nditer_pywrap.c:1969–2041

}

NPY_NO_EXPORT PyObject *
npyiter_seq_item(NewNpyArrayIterObject *self, Py_ssize_t i)
{
    npy_intp ret_ndim;
    npy_intp nop, innerloopsize, innerstride;
    char *dataptr;
    PyArray_Descr *dtype;
    int has_external_loop;
    Py_ssize_t i_orig = i;

    if (self->iter == NULL || self->finished) {
        PyErr_SetString(PyExc_ValueError,
                "Iterator is past the end");
        return NULL;
    }

    if (NpyIter_HasDelayedBufAlloc(self->iter)) {
        PyErr_SetString(PyExc_ValueError,
                "Iterator construction used delayed buffer allocation, "
                "and no reset has been done yet");
        return NULL;
    }
    nop = NpyIter_GetNOp(self->iter);

    /* Negative indexing */
    if (i < 0) {
        i += nop;
    }

    if (i < 0 || i >= nop) {
        PyErr_Format(PyExc_IndexError,
                "Iterator operand index %zd is out of bounds", i_orig);
        return NULL;
    }

#if 0
    /*
     * This check is disabled because it prevents things like
     * np.add(it[0], it[1], it[2]), where it[2] is a write-only
     * parameter.  When write-only, the value of it[i] is
     * likely random junk, as if it were allocated with an
     * np.empty(...) call.
     */
    if (!self->readflags[i]) {
        PyErr_Format(PyExc_RuntimeError,
                "Iterator operand %zd is write-only", i);
        return NULL;
    }
#endif

    dataptr = self->dataptrs[i];
    dtype = self->dtypes[i];
    has_external_loop = NpyIter_HasExternalLoop(self->iter);

    if (has_external_loop) {
        innerloopsize = *self->innerloopsizeptr;
        innerstride = self->innerstrides[i];
        ret_ndim = 1;