Batch querysets without slicing them for .update() etc.

queryset_in_batches.py

def queryset_in_batches_non_slicing(queryset, chunk_size=1000):
    """
    Iterate over a Django queryset that is ordered by primary key.

    Differs from `queryset_batch_iterator` by not slicing the queryset and filters naively on
    upper and lower bounds using pk and chunk size. This allows queryset operations to be performed
    such as `.update()` and `.delete()`
    """

    pk = 0
    queryset = queryset.order_by('pk')

    last_element = queryset.last()

    # Empty queryset
    if last_element is None:
        return

    while pk < last_element.pk:
        prev_pk = pk
        pk = pk + chunk_size
        queryset_to_yield = queryset.filter(pk__gt=prev_pk, pk__lte=pk)
        yield queryset_to_yield