迁移服务平台促销活动

# 示例代码：促销活动管理系统

class PromotionActivity:
    def __init__(self, name, discount_rate, start_date, end_date):
        self.name = name
        self.discount_rate = discount_rate
        self.start_date = start_date
        self.end_date = end_date

    def is_active(self, current_date):
        return self.start_date <= current_date <= self.end_date

    def apply_discount(self, original_price):
        if self.is_active(datetime.now()):
            return original_price * (1 - self.discount_rate)
        else:
            return original_price

# 使用示例
from datetime import datetime

promotion = PromotionActivity(
    name="Summer Sale",
    discount_rate=0.2,
    start_date=datetime(2023, 6, 1),
    end_date=datetime(2023, 8, 31)
)

original_price = 1000
discounted_price = promotion.apply_discount(original_price)
print(f"Original Price: ${original_price}, Discounted Price: ${discounted_price}")