def pre_save(self, model_instance, add):
        return getattr(model_instance, self.attname)
returns subset of os.walk
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/db/models/fields/__init__.py/Field.pre_save--crossover with--dataset/ETHPy150Open FredHutch/swift-commander/swift_commander/swsymlinks.py/mywalk