@hybrid_property
    def redeemable(self):
        """
        Return coupons that are still redeemable. Coupons will become invalid
        once they run out on save. We want to explicitly do a date check to
        avoid having to hit Stripe's API to get back potentially valid codes.

        :return: SQLAlchemy query object
        """
        is_redeemable = or_(self.redeem_by.is_(None),
                            self.redeem_by >= datetime.datetime.now(pytz.utc))

        return and_(self.valid, is_redeemable)
dataset/ETHPy150Open nickjj/build-a-saas-app-with-flask/catwatch/blueprints/billing/models/coupon.py/Coupon.redeemable/original