Python OOP Zero to Hero Practice Test

Master Object-Oriented Programming in Python with Comprehensive Exercises

python object oriented programming concepts

Key Takeaways

Comprehensive Coverage: This practice test encompasses a wide range of OOP concepts from basic to advanced levels.
Diverse Question Types: Includes multiple-choice questions, fill-in-the-blanks, and full coding challenges to enhance understanding.
Real-World Applications: Incorporates LeetCode-level problems to prepare you for real-world programming scenarios.

Easy Section

Multiple Choice Questions (MCQs)

What is the primary purpose of a class in Python?
a) To store data
b) To define a blueprint for creating objects
c) To execute code
d) To import modules

Answer: b) To define a blueprint for creating objects
Which keyword is used to create a class in Python?
a) def
b) class
c) object
d) new

Answer: b) class
What is the output of the following code?
python class Dog: def __init__(self, name): self.name = name dog = Dog("Buddy") print(dog.name) ```
a) None
b) Buddy
c) Dog
d) Error

Answer: b) Buddy

Fill in the Blanks

The ______ method is automatically called when an object is created from a class.
Answer: __init__
In Python, the ______ keyword is used to refer to the current instance of a class.
Answer: self
To make a method private in Python, you prefix its name with ______.
Answer: __ (double underscore)

Coding Questions

Write a Python class named Car with the following attributes:

make (string)
model (string)
year (integer)

Include a method display_info() that prints the car's details in the format:
"Make: [make], Model: [model], Year: [year]"

Answer:

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

    def display_info(self):
        print(f"Make: {self.make}, Model: {self.model}, Year: {self.year}")

car = Car("Toyota", "Corolla", 2020)
car.display_info()

Define a Python class Rectangle with attributes length and width, and a method area() that returns the area of the rectangle.

Answer:

class Rectangle:
    def __init__(self, length, width):
        self.length = length
        self.width = width

    def area(self):
        return self.length * self.width

rect = Rectangle(5, 10)
print(rect.area())  # Output: 50

Medium Section

Multiple Choice Questions (MCQs)

What is the output of the following code?
python class Animal: def speak(self): print("Animal speaks") class Dog(Animal): def speak(self): print("Dog barks") dog = Dog() dog.speak() ```
a) Animal speaks
b) Dog barks
c) Error
d) None

Answer: b) Dog barks
Which of the following is an example of encapsulation?
a) Using private attributes with getters and setters
b) Inheriting from a base class
c) Overriding a method in a subclass
d) Using multiple inheritance

Answer: a) Using private attributes with getters and setters
What does the isinstance() function do in Python?
a) Checks if a class is a subclass of another
b) Checks if an object is an instance of a specific class
c) Creates a new instance of a class
d) Deletes an instance of a class

Answer: b) Checks if an object is an instance of a specific class

Fill in the Blanks

The ______ function is used to check if an object is an instance of a specific class.
Answer: isinstance()
In Python, you can use the ______ method to define how an object should be represented as a string.
Answer: __str__
Complete the inheritance syntax:
python class Person: def __init__(self, name, age): self.name = name self.age = age class Student(____): def __init__(self, name, age, student_id): super().__init__(name, age) self.student_id = student_id ```
Answer: Person

Coding Questions

Create a Python class BankAccount with the following attributes:

account_holder_name (string)
balance (float)

Include the following methods:

deposit(amount) – adds the amount to the balance.
withdraw(amount) – subtracts the amount from the balance if sufficient funds are available, otherwise prints "Insufficient funds".

Answer:

class BankAccount:
    def __init__(self, account_holder_name, balance=0.0):
        self.account_holder_name = account_holder_name
        self.balance = balance

    def deposit(self, amount):
        self.balance += amount
        print(f"Deposited ${amount}. New balance: ${self.balance}")

    def withdraw(self, amount):
        if amount > self.balance:
            print("Insufficient funds")
        else:
            self.balance -= amount
            print(f"Withdrew ${amount}. New balance: ${self.balance}")

account = BankAccount("John Doe", 1000.0)
account.deposit(500.0)
account.withdraw(200.0)
account.withdraw(1500.0)

Create a Python class Student that inherits from a base class Person. The Person class has attributes name and age. The Student class adds an attribute student_id and a method display_info() that prints all attributes.

Answer:

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

class Student(Person):
    def __init__(self, name, age, student_id):
        super().__init__(name, age)
        self.student_id = student_id

    def display_info(self):
        print(f"Name: {self.name}, Age: {self.age}, Student ID: {self.student_id}")

student = Student("Alice", 20, "S12345")
student.display_info()

Hard Section

Multiple Choice Questions (MCQs)

What is the output of the following code?
python class A: def __init__(self): self.x = 1 class B(A): def __init__(self): super().__init__() self.y = 2 b = B() print(b.x, b.y) ```
a) 1 2
b) 2 1
c) Error
d) None

Answer: a) 1 2
Which of the following is an example of polymorphism?
a) A class inheriting from multiple classes
b) A method having the same name in different classes
c) A class overriding a method from its parent class
d) Both b and c

Answer: d) Both b and c
What does the @staticmethod decorator indicate in Python?
a) The method requires the self parameter and can be called on an instance.
b) The method does not require the self parameter and can be called on the class itself.
c) The method can access class-level variables.
d) None of the above.

Answer: b) The method does not require the self parameter and can be called on the class itself.

Fill in the Blanks

The ______ method is used to define how an object should be compared for equality.
Answer: __eq__
In Python, the ______ function is used to delete an attribute from an object.
Answer: delattr()
Complete the multi-level inheritance structure:
python class A: def display(self): print("I am in Class A") class B(A): def display(self): super().display() print("I am in Class B") class C(B): def display(self): super().display() print("I am in Class C") obj = C() obj.display() ```
Expected Output:
``` I am in Class A I am in Class B I am in Class C ```

Coding Challenges

Data Management System

Create a Python program with the following requirements:

A class called Contact that has attributes – name, phone, and email.
A manager class ContactManager that uses a list to store Contact objects.
Implement the following methods in ContactManager:

add_contact(contact): Adds a new contact to the list.
delete_contact(name): Deletes a contact by name.
get_all_contacts(): Displays all contacts.

Example Usage:

manager = ContactManager()
contact1 = Contact("Alice", "1234", "alice@example.com")
manager.add_contact(contact1)
manager.get_all_contacts()
manager.delete_contact("Alice")

Answer:

class Contact:
    def __init__(self, name, phone, email):
        self.name = name
        self.phone = phone
        self.email = email

class ContactManager:
    def __init__(self):
        self.contacts = []

    def add_contact(self, contact):
        self.contacts.append(contact)
        print(f"Added contact: {contact.name}")

    def delete_contact(self, name):
        for contact in self.contacts:
            if contact.name == name:
                self.contacts.remove(contact)
                print(f"Deleted contact: {name}")
                return
        print(f"Contact {name} not found.")

    def get_all_contacts(self):
        print("All Contacts:")
        for contact in self.contacts:
            print(f"Name: {contact.name}, Phone: {contact.phone}, Email: {contact.email}")

manager = ContactManager()
contact1 = Contact("Alice", "1234", "alice@example.com")
manager.add_contact(contact1)
manager.get_all_contacts()
manager.delete_contact("Alice")
manager.get_all_contacts()

Find Matching Shapes

Implement a Python program using OOP to solve the following:

You are provided with a Shape class that has the attribute area. Subclasses Rectangle and Circle override the calculate_area() method to compute their respective areas.

Write a function find_shapes_over_area(shapes, threshold) that accepts:

A list of various shape objects.
A threshold value.

The function should return a list of shapes where the area is greater than the threshold.

Example Usage:

shapes = [Rectangle(5, 10), Circle(7), Rectangle(2, 8)]
filtered_shapes = find_shapes_over_area(shapes, 50)
print(filtered_shapes)  # Returns only the shapes whose areas > 50

Answer:

import math

class Shape:
    def __init__(self):
        self.area = 0

    def calculate_area(self):
        pass

class Rectangle(Shape):
    def __init__(self, length, width):
        super().__init__()
        self.length = length
        self.width = width
        self.calculate_area()

    def calculate_area(self):
        self.area = self.length * self.width

class Circle(Shape):
    def __init__(self, radius):
        super().__init__()
        self.radius = radius
        self.calculate_area()

    def calculate_area(self):
        self.area = math.pi * (self.radius ** 2)

def find_shapes_over_area(shapes, threshold):
    return [shape for shape in shapes if shape.area > threshold]

shapes = [Rectangle(5, 10), Circle(7), Rectangle(2, 8)]
filtered_shapes = find_shapes_over_area(shapes, 50)
for shape in filtered_shapes:
    print(f"{shape.__class__.__name__} with area {shape.area}")

Conclusion

Mastering Object-Oriented Programming in Python requires a solid understanding of core concepts such as classes, objects, inheritance, polymorphism, and encapsulation. This practice test is designed to guide you from foundational knowledge to advanced application through a structured progression of questions. By diligently working through the Easy, Medium, and Hard sections, you will develop the skills necessary to tackle real-world programming challenges with confidence.

References

Last updated January 19, 2025