Problems on Class and object
1. Define a Basic Class
Problem:
Create a class Car with attributes brand, model, and year.
Add a method start_engine() that prints a message like:
"The 2022 Tesla Model S engine has started."
Explanation:
Introduces the concept of defining a class, using the constructor (__init__), and creating methods that use instance data.
Sample Input:
car1 = Car("Tesla", "Model S", 2022)
car1.start_engine()
Sample Output:
The 2022 Tesla Model S engine has started.
2. Class Representing a Movie
Problem:
Create a class Movie with attributes title, director, and rating.
Add a method describe() that prints details like:
"Inception directed by Christopher Nolan has a rating of 9.0."
Explanation:
Shows how to represent real-world entities and display their information through methods.
Sample Input:
movie1 = Movie("Inception", "Christopher Nolan", 9.0)
movie1.describe()
Sample Output:
Inception directed by Christopher Nolan has a rating of 9.0.
3. Shopping Cart with Total Calculation
Problem:
Create a class ShoppingCart that stores items and prices.
Add methods:
add_item(name, price)total()— returns the total price
Explanation:
Teaches how to store multiple data (lists or dictionaries) inside objects and operate on them using methods.
Sample Input:
cart = ShoppingCart()
cart.add_item("Book", 250)
cart.add_item("Pen", 30)
cart.total()
Sample Output:
Total: ₹280
4. Track Employee Bonuses
Problem:
Create a class Employee with name and salary.
Add a method apply_bonus(percent) that increases the salary by a percentage.
Explanation:
Practices modifying attributes and applying formulas within methods.
Sample Input:
emp = Employee("Aman", 50000)
emp.apply_bonus(10)
Sample Output:
Bonus applied. New salary: ₹55000.0
5. Temperature Converter
Problem:
Create a class Temperature with a Celsius value.
Add methods:
to_fahrenheit()to_kelvin()
Explanation:
Shows conversion logic and returning computed values via methods.
Sample Input:
t = Temperature(25)
print(t.to_fahrenheit())
print(t.to_kelvin())
Sample Output:
77.0
298.15
6. Simple Library System
Problem:
Create a class Book with title, author, and is_available=True.
Add:
borrow()→ makes it unavailablereturn_book()→ makes it available again
Explanation:
Demonstrates state changes using boolean attributes.
Sample Input:
book1 = Book("Harry Potter", "J.K. Rowling")
book1.borrow()
book1.return_book()
Sample Output:
Book borrowed successfully.
Book returned successfully.
7. Simple Bank Account with Validation
Problem:
Create a class BankAccount with holder_name and balance=0.
Add:
deposit(amount)withdraw(amount)(only if balance ≥ amount)display_balance()
Explanation:
Shows conditional logic and secure data updates within an object.
Sample Input:
acc = BankAccount("Ravi")
acc.deposit(1000)
acc.withdraw(300)
acc.display_balance()
Sample Output:
Deposited ₹1000
Withdrew ₹300
Current balance: ₹700
8. Class for Student Marks
Problem:
Create a class Student that stores name and three subject marks.
Add:
average()→ returns average marksgrade()→ returns grade based on average
Explanation:
Combines arithmetic and conditional logic with OOP.
Sample Input:
student1 = Student("Anita", 75, 85, 90)
print(student1.average())
print(student1.grade())
Sample Output:
83.33
A
9. Car Mileage Tracker
Problem:
Create a class MileageTracker with distance and fuel_used.
Add a method calculate_mileage() that returns distance ÷ fuel.
If fuel is 0, handle it gracefully.
Explanation:
Shows how to handle invalid data or prevent runtime errors inside a method.
Sample Input:
trip = MileageTracker(400, 20)
print(trip.calculate_mileage())
Sample Output:
Mileage: 20.0 km/l
10. Product Discount System
Problem:
Create a class Product with name, price, and category.
Add:
apply_discount(percent)— reduces price by that percentdisplay_info()— prints product info
Explanation:
Focuses on modifying and displaying data in an organized way.
Sample Input:
p = Product("Laptop", 60000, "Electronics")
p.apply_discount(10)
p.display_info()
Sample Output:
Product: Laptop | Category: Electronics | Price after discount: ₹54000.0