虚拟主播优惠卷

import datetime

class Coupon:
    def __init__(self, code, discount_type, value, expiration_date):
        self.code = code
        self.discount_type = discount_type
        self.value = value
        self.expiration_date = expiration_date

def is_valid(coupon):
    return datetime.datetime.now() < coupon.expiration_date

def apply_coupon(coupon, total_amount):
    if not is_valid(coupon):
        return "Coupon has expired."
    
    if coupon.discount_type == "percentage":
        return total_amount * (1 - coupon.value / 100)
    elif coupon.discount_type == "fixed":
        return max(total_amount - coupon.value, 0)
    else:
        return total_amount

# Example usage
coupon = Coupon(code="SAVE20", discount_type="percentage", value=20, expiration_date=datetime.datetime(2023, 12, 31))
total_amount = 100
discounted_amount = apply_coupon(coupon, total_amount)
print(f"Discounted Amount: ${discounted_amount}")