离线存储优惠卷

class Coupon:
    def __init__(self, code, discount_type, value, expiration_date):
        self.code = code
        self.discount_type = discount_type  # 'percentage', 'fixed', 'cashback'
        self.value = value
        self.expiration_date = expiration_date

    def is_valid(self, current_date):
        return current_date <= self.expiration_date

    def apply_discount(self, price):
        if self.discount_type == 'percentage':
            return price * (1 - self.value / 100)
        elif self.discount_type == 'fixed':
            return max(0, price - self.value)
        elif self.discount_type == 'cashback':
            return price  # Cashback is applied after purchase

# Example usage
current_date = '2023-10-01'
coupon = Coupon(code='SAVE20', discount_type='percentage', value=20, expiration_date='2023-12-31')

if coupon.is_valid(current_date):
    original_price = 100
    discounted_price = coupon.apply_discount(original_price)
    print(f"Original Price: ${original_price}, Discounted Price: ${discounted_price}")
else:
    print("Coupon has expired.")