Method __getitem__

ormar/queryset/queryset.py:1499–1534

Returns a new ``QuerySet`` with LIMIT/OFFSET derived from a Python integer index or slice. Negative indices and negative slice bounds are translated into a reversed-order query plus an in-memory list reversal on ``.all()``, so that ``Model.objects[-N:]`` ret

(self, key: Union[int, slice])

        )

    def __getitem__(self, key: Union[int, slice]) -> "QuerySet[T]":
        """
        Returns a new ``QuerySet`` with LIMIT/OFFSET derived from a Python
        integer index or slice.

        Negative indices and negative slice bounds are translated into a
        reversed-order query plus an in-memory list reversal on ``.all()``,
        so that ``Model.objects[-N:]`` returns the last ``N`` rows in the
        original ordering. Slice shapes that would require a ``COUNT(*)``
        round-trip (a bare ``[:-N]``, or mixed positive/negative bounds) are
        rejected with a ``QueryDefinitionError``; use ``.count()`` combined
        with ``.offset()``/``.limit()`` instead.

        Each call replaces the previous pagination state rather than composing
        with it — subsequent slicing on an already-sliced queryset is not
        guaranteed to compose in a Python-list-like way.

        :param key: integer index or slice
        :type key: int | slice
        :raises QueryDefinitionError: when ``key`` is not an ``int``/``slice``
            or when the slice cannot be expressed without a count
        :return: new QuerySet with updated pagination
        :rtype: QuerySet
        """
        bounds = normalize_slice(key)
        order_bys = self.order_bys
        if self._reverse_result != bounds.reverse:
            if not order_bys:
                order_bys = OrderAction.from_model_defaults(self.model)
            order_bys = [ob.flipped() for ob in order_bys]
        return self.rebuild_self(
            limit_count=bounds.limit,
            offset=bounds.offset,
            order_bys=order_bys,
            reverse_result=bounds.reverse,
        )