Tell us what’s happening:
I found someone else that is having this issue, and their solution did not work for me. I have code that is doing exactly what the step is asking for, but it is throwing an error that makes no sense.
It is erroring out with:
Your output should match the format: Best price for {product.name} for {user_tier} user: ${best_price:.2f}
My original code had the formatter at 0.2f to insure a zero showed up if the price was under a dollar, but copied the format line in. I get the expected output,
Your code so far
from abc import ABC, abstractmethod
class Product:
def __init__(self, name: str, price: float) -> None:
self.name = name
self.price = price
def __str__(self) -> str:
return f'{self.name} - ${self.price}'
class DiscountStrategy(ABC):
@abstractmethod
def is_applicable(self, product: Product, user_tier: str) -> bool:
pass
@abstractmethod
def apply_discount(self, product: Product) -> float:
pass
class PercentageDiscount(DiscountStrategy):
def __init__(self, percent: int) -> None:
self.percent = percent
def is_applicable(self, product: Product, user_tier: str) -> bool:
return self.percent <= 70
def apply_discount(self, product: Product) -> float:
return product.price * (1 - self.percent / 100)
class FixedAmountDiscount(DiscountStrategy):
def __init__(self, amount: int) -> None:
self.amount = amount
def is_applicable(self, product: Product, user_tier: str) -> bool:
return product.price * 0.9 > self.amount
def apply_discount(self, product: Product) -> float:
return product.price - self.amount
class PremiumUserDiscount(DiscountStrategy):
def is_applicable(self, product: Product, user_tier: str) -> bool:
return user_tier.lower() == 'premium'
def apply_discount(self, product: Product) -> float:
return product.price * 0.8
class DiscountEngine:
def __init__(self, strategies: list[DiscountStrategy]) -> None:
self.strategies = strategies
def calculate_best_price(self, product: Product, user_tier: str) -> float:
prices = [product.price]
for strategy in self.strategies:
if strategy.is_applicable(product, user_tier):
discounted = strategy.apply_discount(product)
prices.append(discounted)
return min(prices)
if __name__ == '__main__':
product = Product('Wireless mouse', 50.0)
user_tier = 'Premium'
strategies = [
PercentageDiscount(10),
FixedAmountDiscount(5),
PremiumUserDiscount()
]
engine = DiscountEngine(strategies)
best_price = engine.calculate_best_price(product, user_tier)
# User Editable Region
print(f"Best price for {product.name} for {user_tier} user: ${best_price:.2f}")
# User Editable Region
Your browser information:
User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6.2 Safari/605.1.15
Challenge Information:
Build a Discount Calculator - Step 31
