Pizza Pricing

easy · decorator

Brief-reported interview attribution (unverified): Amazon

Design a pizza ordering system. There are three base pizzas — Margherita $5, Farmhouse $7, Pepperoni $8 — and four toppings — Extra Cheese +$1, Mushroom +$1, Jalapeno +$1, Olives +$2. A topping decorates a pizza: it wraps it, adds its price, and extends its description. Toppings stack (the same topping twice counts twice). An Order holds several pizzas and totals them.

class Pizza:
    def price(self):
        # -> total price in dollars
    def description(self):
        # -> e.g. "Margherita + Mushroom + Olives"

# Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8)
# Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1),
#                                Jalapeno (+$1), Olives (+$2)

class Order:
    def __init__(self):
    def add_pizza(self, pizza):
    def total(self):
        # -> sum of the pizzas' prices
    def bill(self):
        # -> [(description, price), ...] one entry per pizza, in order

Rules. Every pizza — base or topped — is a Pizza: price() and description() work on any of them. A topping's description is the inner pizza's description plus " + " plus the topping name. An empty order totals 0 and its bill is [].

Money units: prices are whole dollars, not cents; a plain Margherita costs 5.

Tests use explicit inputs and injected clocks/callbacks. No network, real threads or application-server execution is involved.

Public demo

# Public demo: run after implementing the class API above.
print(Margherita().price())
print(Farmhouse().price())
print(Pepperoni().price())
print(Margherita().description())

Starter code

class Pizza:

    def price(self):
        """-> total price in dollars"""
        pass

    def description(self):
        """-> e.g. "Margherita + Mushroom + Olives" Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8) Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1), Jalapeno (+$1), Olives (+$2)"""
        pass

class Margherita(Pizza):

    def price(self):
        """-> total price in dollars"""
        pass

    def description(self):
        """-> e.g. "Margherita + Mushroom + Olives" Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8) Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1), Jalapeno (+$1), Olives (+$2)"""
        pass

class Farmhouse(Pizza):

    def price(self):
        """-> total price in dollars"""
        pass

    def description(self):
        """-> e.g. "Margherita + Mushroom + Olives" Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8) Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1), Jalapeno (+$1), Olives (+$2)"""
        pass

class Pepperoni(Pizza):

    def price(self):
        """-> total price in dollars"""
        pass

    def description(self):
        """-> e.g. "Margherita + Mushroom + Olives" Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8) Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1), Jalapeno (+$1), Olives (+$2)"""
        pass

class _Topping(Pizza):

    def __init__(self, pizza, name, price):
        """Initialize the state described in the problem."""
        pass

    def price(self):
        """-> total price in dollars"""
        pass

    def description(self):
        """-> e.g. "Margherita + Mushroom + Olives" Base pizzas: Margherita ($5), Farmhouse ($7), Pepperoni ($8) Toppings (each wraps a Pizza): ExtraCheese (+$1), Mushroom (+$1), Jalapeno (+$1), Olives (+$2)"""
        pass

class ExtraCheese(_Topping):

    def __init__(self, pizza):
        """Initialize the state described in the problem."""
        pass

class Mushroom(_Topping):

    def __init__(self, pizza):
        """Initialize the state described in the problem."""
        pass

class Jalapeno(_Topping):

    def __init__(self, pizza):
        """Initialize the state described in the problem."""
        pass

class Olives(_Topping):

    def __init__(self, pizza):
        """Initialize the state described in the problem."""
        pass

class Order:

    def __init__(self):
        """Initialize the state described in the problem."""
        pass

    def add_pizza(self, pizza):
        """Implement the return value and rules in the API contract."""
        pass

    def total(self):
        """-> sum of the pizzas' prices"""
        pass

    def bill(self):
        """-> [(description, price), ...] one entry per pizza, in order"""
        pass

Loading editor…

Each test has a five-second execution limit. Your practice drafts and solved progress stay in this browser.

Return to the Python compiler