Creating objects in Python - Practice Exercises

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Python code creating an object?

Consider this class and object creation code. What will be printed when running it?

Python

class Car:
    def __init__(self, brand, year):
        self.brand = brand
        self.year = year

my_car = Car('Toyota', 2020)
print(my_car.brand, my_car.year)

A brand year

B Car object at memory address

C Error: attribute not found

D Toyota 2020

💡 Hint

Look at how the __init__ method assigns values to self.brand and self.year.

The __init__ method sets the brand and year attributes. Printing them shows 'Toyota 2020'.

❓ Predict Output

intermediate

What is the output of this code creating multiple objects?

This code creates two objects from the Person class. What will it print?

Python

class Person:
    def __init__(self, name):
        self.name = name

p1 = Person('Alice')
p2 = Person('Bob')
print(p1.name, p2.name)

A Error: name attribute missing

B Bob Alice

C Alice Bob

D Person Person

💡 Hint

Each object has its own name attribute set during creation.

p1.name is 'Alice' and p2.name is 'Bob', so printing both shows 'Alice Bob'.

🔧 Debug

advanced

What error does this code raise when creating an object?

This code tries to create an object but has a mistake. What error will it raise?

Python

class Animal:
    def __init__(self, species):
        self.species = species

pet = Animal()

A TypeError: __init__() missing 1 required positional argument: 'species'

B AttributeError: 'Animal' object has no attribute 'species'

C NameError: name 'Animal' is not defined

D No error, pet.species is None

💡 Hint

Check if the constructor requires any arguments and if they are provided.

The __init__ method requires 'species' argument, but none was given, causing TypeError.

❓ Predict Output

advanced

What is the output of this code using a method in an object?

This code defines a class with a method. What will it print when calling greet()?

Python

class Greeter:
    def __init__(self, name):
        self.name = name
    def greet(self):
        return f'Hello, {self.name}!'

g = Greeter('Sam')
print(g.greet())

A greet

B Hello, Sam!

C Hello, name!

D Error: greet() missing 1 required positional argument

💡 Hint

The greet method returns a greeting string using the object's name attribute.

Calling g.greet() returns 'Hello, Sam!' which is printed.

🧠 Conceptual

expert

How many objects are created after running this code?

Consider this code snippet. How many distinct objects are created in memory?

Python

class Box:
    def __init__(self, content):
        self.content = content

b1 = Box('apple')
b2 = Box('banana')
b3 = b1
b4 = Box('apple')

A 3

B 4

C 2

D 1

💡 Hint

Remember that assigning b3 = b1 does not create a new object.

b1, b2, and b4 create new Box objects. b3 just points to b1's object. So total 3 objects.