@property
    def activities(self):
        if self._activities is None:
            self._activities = DailyActivity.objects.filter(
                user__in=self.cohort.users,
                days__range=(self.start_day, self.end_day - 1)
            )
        return self._activities
dataset/ETHPy150Open MontmereLimited/django-lean/django_lean/lean_retention/reports.py/Period.activities/original