class Order: def __init__(self, discount=0.5): self.product = Product() self.customer = Customer() self.discount = Decimal(discount) def get_order_price(self): product_price = self.get_product_price() shipping_price = self.get_shipping_price() total = (product_price + shipping_price) * self.discount return total def get_product_price(self): return self.product.get_price() def get_shipping_price(self): return self.customer.calculate_shipping_price()