Pythonic Getters and Setters

lesson_setter_decorator.py

class Customer:
    __slots__ = ['member_discount']

def __init__(self, member_discount:float):
    self.member_discount = member_discount


class Product:
    __slots__ = ['_price', '_discounted_price', '_color_way']

    def __init__(self, price:float, discounted_price:float, color_way:str,):
        self._price = price
        self._discounted_price = discounted_price
        self._color_way = color_way

    @property
    def color_way(self):
        return self._color_way

    @property
    def price(self):
        return self._price

    @property # -> getter
    def discounted_price(self) -> float:
        return self._discounted_price

    @discounted_price.setter # -> setter
    def discounted_price(self, value:float):
        self._discounted_price = value

# data retrieved from API
product_data:dict = { 'price': 50., 'discounted_price': 0, 'color_way': 'red+black'  }
customer_data:dict = {'member_discount': .25 }

# hydrate customer
customer:Customer = Customer(**customer_data)

# hydrate product
sneakers:Product = Product(**product_data)

# calculate discount
def calc_discount(price:float, discount:float) -> float:
    return price - (price * discount)

# apply discount only for specific color way
if sneakers.color_way == 'red+black':
    # simple property assignment uses `setter` under the hood
    sneakers.discounted_price = calc_discount(sneakers.price, customer.member_discount)
    print('after discount: ', sneakers.discounted_price)