def _existing_object(self, pk):
        if not hasattr(self, '_object_dict'):
            self._object_dict = {}
        if not pk:
            return None
        try:
            obj = self.get_queryset().get(pk=pk)
        except ObjectDoesNotExist:
            return None
        else:
            self._object_dict[obj.pk] = obj
        return super(ThumbFormSet, self)._existing_object(pk)
Reads the babyboom data.
dataset/ETHPy150Open theatlantic/django-cropduster/cropduster/views/forms.py/ThumbFormSet._existing_object--crossover with--dataset/ETHPy150Open AllenDowney/DataExploration/analytic.py/ReadBabyBoom