Python Classes and Objects Exercises With Answers

Which method initialises a new object?

1. __main__
2. __start__
3. __init__correct
4. init

Answer: __init__

Why: __init__ runs automatically when an instance is created.

What does self refer to inside a method?

1. The class
2. The module
3. The current instancecorrect
4. The parent class

Answer: The current instance

Why: self is the object on which the method was called.

How do you create an instance of Order?

1. Order("latte", 4.5)correct
2. Order.new(...)
3. new Order(...)
4. Order.init(...)

Answer: Order("latte", 4.5)

Why: Call the class like a function to create an instance.

What is an attribute?

1. A function outside a class
2. A file path
3. Data stored on an objectcorrect
4. A loop variable

Answer: Data stored on an object

Why: Attributes hold the state of a particular object.

Complete the method name that initialises the object.

class Order:
    def ____(self, drink):
        self.drink = drink

Answer: __init__

Why: __init__ is the initialiser method.

Complete the attribute assignment for the drink parameter.

class Order:
    def __init__(self, drink):
        self.____ = drink

Answer: drink

Why: self.drink stores the parameter on the instance.

Complete the expression that multiplies price by quantity.

class Order:
    def total(self):
        return self.price ____ self.quantity

Answer: *

Why: self.price * self.quantity uses the object's own attributes.

Complete the call that creates an Order instance.

order = ____("latte", 4.5)
print(order.price)

Answer: Order

Why: The class name followed by parentheses creates an instance.

What is printed?

class A:
    def __init__(self, x):
        self.x = x
print(A(3).x)

Answer: 3

Why: The instance stores 3 in its x attribute.

What is the output?

class A:
    def value(self):
        return 7
print(A().value())

Answer: 7

Why: The method returns 7.

What does this code print?

class Order:
    def __init__(self, price, quantity=2):
        self.price = price
        self.quantity = quantity
print(Order(4).price * Order(4).quantity)

Answer: 8

Why: Each Order gets price 4 and quantity 2, so the product is 8.

What does the program output?

class A:
    pass
print(A().__class__.__name__)

Answer: A

Why: The class name is A.