gistfile1.py

@classmethod
def prefetch_related(cls, instances):
    pass

@classmethod
def prefetcher(cls, instances, queryset, fk_attr):
    cache = {}
    for instance in instances:
        cache[getattr(instance, fk_attr + '_id')] = instance

    for foreign in queryset.filter(pk__in=cache.keys()):
        setattr(cache[foreign.pk], fk_attr, foreign)

< loic84> Dog.prefetcher(dogs, Puppy.objects.filter(cute=True), 'parent')
< loic84> well there are 3 arguments, the first one is your instances that are already fetched.
< loic84> for example dogs = Dog.objects.filter(age__gt=2)
< loic84> then the QS is whatever you want to "prefetch".
< loic84> and the third argument is the name of the attribute (FK attname basically) that will be used to attach the prefetched item to the parent item.