109 lines
3.3 KiB
Python
109 lines
3.3 KiB
Python
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# https://stepik.org/lesson/701985/step/11?unit=702086
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from typing import Protocol
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class Validator(Protocol):
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def validate(self, value: str) -> bool:
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...
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class ValidatedField:
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ValueValidator: Validator
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def __init__(self, *args, **kwargs):
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self.validator = self.ValueValidator(*args, **kwargs)
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def __set_name__(self, owner, name):
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self.name = "_" + name
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def __get__(self, instance, owner):
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return getattr(instance, self.name)
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def __set__(self, instance, value):
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if self.validator.validate(value):
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setattr(instance, self.name, value)
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class StringValue(ValidatedField):
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class ValueValidator(Validator):
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def __init__(self, min_length, max_length):
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self.min_length, self.max_length = min_length, max_length
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def validate(self, value: str) -> bool:
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return (
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isinstance(value, str)
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and self.min_length <= len(value) <= self.max_length
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)
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class PriceValue(ValidatedField):
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class ValueValidator(Validator):
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def __init__(self, max_value):
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self.max_value = max_value
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def validate(self, value: str) -> bool:
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return isinstance(value, int) and 0 <= value <= self.max_value
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class Product:
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name = StringValue(min_length=2, max_length=50)
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price = PriceValue(max_value=10000)
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def __init__(self, name, price):
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self.name = name
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self.price = price
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class SuperShop:
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def __init__(self, name):
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self.name = name
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self.goods: list[Product] = []
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def add_product(self, product: Product):
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self.goods.append(product)
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def remove_product(self, product: Product):
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self.goods.remove(product)
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shop = SuperShop("У Балакирева")
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shop.add_product(Product("Курс по Python", 0))
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shop.add_product(Product("Курс по Python ООП", 2000))
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for p in shop.goods:
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print(f"{p.name}: {p.price}")
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def tests():
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shop = SuperShop("У Балакирева")
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shop.add_product(Product("name", 100))
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shop.add_product(Product("name", 100))
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assert (
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shop.name == "У Балакирева"
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), "атрибут name объекта класса SuperShop содержит некорректное значение"
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for p in shop.goods:
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assert p.price == 100, "дескриптор price вернул неверное значение"
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assert p.name == "name", "дескриптор name вернул неверное значение"
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t = Product("name 123", 1000)
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shop.add_product(t)
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shop.remove_product(t)
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assert (
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len(shop.goods) == 2
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), "неверное количество товаров: возможно некорректно работают методы add_product и remove_product"
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assert hasattr(shop.goods[0], "name") and hasattr(shop.goods[0], "price")
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t = Product(1000, "name 123")
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if hasattr(t, "_name"):
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assert type(t.name) == str, "типы поля name должнен быть str"
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if hasattr(t, "_price"):
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assert type(t.price) in (
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int,
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float,
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), "тип поля price должнен быть int или float"
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tests()
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