Python Practice | Tech Bridge24

Class and Objects Practice

Define classes, create objects and work with instance attributes and methods.

Define a Class and Create an Object

Easy

Write a class Student with attribute name. Create an object with name from input and print it.

Input Format

A single line containing a name.

Output Format

Print the student name.

Sample Test Cases

Sample Input 1 Ravi	Sample Output 1 Ravi
Sample Input 2 Bob	Sample Output 2 Bob
Sample Input 3 Sam	Sample Output 3 Sam

Object with Multiple Attributes

Easy

Write a class Laptop with brand and price attributes. Read both, create an object, and print both.

Input Format

First line: brand. Second line: price.

Output Format

Print 'Brand: [brand]' and 'Price: [price]' on separate lines.

Sample Test Cases

Sample Input 1 Dell 55000	Sample Output 1 Brand: Dell Price: 55000
Sample Input 2 HP 40000	Sample Output 2 Brand: HP Price: 40000
Sample Input 3 Lenovo 60000	Sample Output 3 Brand: Lenovo Price: 60000

Call a Method on an Object

Easy

Write a class Animal with a method sound() that prints 'Some sound'. Create an object and call sound().

Input Format

No input.

Output Format

Print 'Some sound'.

Sample Test Cases

Sample Input 1	Sample Output 1 Some sound
Sample Input 2	Sample Output 2 Some sound
Sample Input 3	Sample Output 3 Some sound

Access Object Attributes

Easy

Write a class Person with name and age. Read both, create an object, and print 'name is age years old'.

Input Format

First line: name. Second line: age.

Output Format

Print the sentence.

Sample Test Cases

Sample Input 1 Alice 25	Sample Output 1 Alice is 25 years old
Sample Input 2 Bob 30	Sample Output 2 Bob is 30 years old
Sample Input 3 Kid 5	Sample Output 3 Kid is 5 years old

Create Multiple Objects

Easy

Write a class Point with x and y. Create two objects (1,2) and (3,4) and print both.

Input Format

No input.

Output Format

Print both points as (x, y), one per line.

Sample Test Cases

Sample Input 1	Sample Output 1 (1, 2) (3, 4)
Sample Input 2	Sample Output 2 (1, 2) (3, 4)
Sample Input 3	Sample Output 3 (1, 2) (3, 4)

Object Method with Argument

Easy

Write a class Dog with a method run(speed) that prints 'Running at [speed] km/h'.

Input Format

A single line containing the speed.

Output Format

Print the running message.

Sample Test Cases

Sample Input 1 20	Sample Output 1 Running at 20 km/h
Sample Input 2 50	Sample Output 2 Running at 50 km/h
Sample Input 3 10	Sample Output 3 Running at 10 km/h

Modify Object Attribute

Easy

Write a class Phone with attribute battery. Create an object with battery 100, read a new value, update it, and print it.

Input Format

A single line containing the new battery value.

Output Format

Print the updated battery.

Sample Test Cases

Sample Input 1 75	Sample Output 1 75
Sample Input 2 50	Sample Output 2 50
Sample Input 3 100	Sample Output 3 100

Print Attribute via Method

Easy

Write a class Movie with title attribute and a method get_title() that returns it.

Input Format

A single line containing a movie title.

Output Format

Print the title.

Sample Test Cases

Sample Input 1 Inception	Sample Output 1 Inception
Sample Input 2 Titanic	Sample Output 2 Titanic
Sample Input 3 Jaws	Sample Output 3 Jaws

Two Objects with Different Values

Easy

Write a class Fruit with name and color. Create objects apple/red and banana/yellow and print each as 'name is color'.

Input Format

No input.

Output Format

Print both descriptions, one per line.

Sample Test Cases

Sample Input 1	Sample Output 1 apple is red banana is yellow
Sample Input 2	Sample Output 2 apple is red banana is yellow
Sample Input 3	Sample Output 3 apple is red banana is yellow

Simple Class with Display

Easy

Write a class Teacher with subject attribute and a method show() that prints the subject.

Input Format

A single line containing a subject.

Output Format

Print the subject.

Sample Test Cases

Sample Input 1 Mathematics	Sample Output 1 Mathematics
Sample Input 2 Science	Sample Output 2 Science
Sample Input 3 Maths	Sample Output 3 Maths

Class with List Attribute

Medium

Write a class Classroom with students list and a method add_student(name). Add 3 students and print the list.

Input Format

Three lines, each containing a student name.

Output Format

Print the list of students.

Sample Test Cases

Sample Input 1 Alice Bob Carol	Sample Output 1 ['Alice', 'Bob', 'Carol']
Sample Input 2 X Y Z	Sample Output 2 ['X', 'Y', 'Z']
Sample Input 3 1 2 3	Sample Output 3 ['1', '2', '3']

Method That Returns a Value

Medium

Write a class Rectangle with length and breadth and a method area() that returns length * breadth.

Input Format

A single line containing two space-separated integers.

Output Format

Print the area.

Sample Test Cases

Sample Input 1 5 8	Sample Output 1 40
Sample Input 2 10 20	Sample Output 2 200
Sample Input 3 3 3	Sample Output 3 9

Object as Method Argument

Medium

Write a class Point with x, y and a method distance_to(other) that returns the Manhattan distance |x1-x2| + |y1-y2|.

Input Format

First line: x and y of point 1. Second line: x and y of point 2.

Output Format

Print the Manhattan distance.

Sample Test Cases

Sample Input 1 1 2 4 6	Sample Output 1 7
Sample Input 2 0 0 3 4	Sample Output 2 7
Sample Input 3 -1 -1 1 1	Sample Output 3 4

Class with Class Attribute

Medium

Write a class Animal with class attribute kingdom = 'Animalia'. Read an animal name, create an object, and print 'name belongs to Animalia'.

Input Format

A single line containing an animal name.

Output Format

Print the sentence.

Sample Test Cases

Sample Input 1 Lion	Sample Output 1 Lion belongs to Animalia
Sample Input 2 Tiger	Sample Output 2 Tiger belongs to Animalia
Sample Input 3	Sample Output 3 belongs to Animalia

Check Object Equality by Attribute

Medium

Write a class Song with title attribute. Read two titles, create two objects, and print 'Same' if titles are equal else 'Different'.

Input Format

First line: title 1. Second line: title 2.

Output Format

Print Same or Different.

Sample Test Cases

Sample Input 1 Believer Believer	Sample Output 1 Same
Sample Input 2 Hello Hi	Sample Output 2 Different
Sample Input 3 A A	Sample Output 3 Same

Object with Default Attribute

Medium

Write a class Bike with color attribute defaulting to 'black'. Read a color, create an object, and print it. If empty input, print 'black'.

Input Format

A single line containing a color (may be empty).

Output Format

Print the bike color.

Sample Test Cases

Sample Input 1 red	Sample Output 1 red
Sample Input 2 blue	Sample Output 2 blue
Sample Input 3	Sample Output 3 black

Nested Object — Address in Person

Medium

Write a class Address with city, and a class Person with name and an Address object. Read name and city, create objects, and print 'name lives in city'.

Input Format

First line: name. Second line: city.

Output Format

Print the sentence.

Sample Test Cases

Sample Input 1 Alice Delhi	Sample Output 1 Alice lives in Delhi
Sample Input 2 Bob Mumbai	Sample Output 2 Bob lives in Mumbai
Sample Input 3 Sam Goa	Sample Output 3 Sam lives in Goa

List of Objects

Medium

Write a class Player with name and score. Read N players, create objects in a list, and print the name of the highest scorer.

Input Format

First line: integer N. Next N lines: name and score space-separated.

Output Format

Print the name of the highest scorer.

Sample Test Cases

Sample Input 1 3 Virat 89 Rohit 64 Dhoni 45	Sample Output 1 Virat
Sample Input 2 2 A 50 B 90	Sample Output 2 B
Sample Input 3 2 X 70 Y 70	Sample Output 3 X

Method Returning Multiple Values

Medium

Write a class Stats with a method min_max(lst) that returns the minimum and maximum of a list.

Input Format

First line: integer N. Second line: N space-separated integers.

Output Format

Print the minimum and maximum space-separated.

Sample Test Cases

Sample Input 1 5 9 2 7 1 5	Sample Output 1 1 9
Sample Input 2 3 5 1 9	Sample Output 2 1 9
Sample Input 3 1 7	Sample Output 3 7 7

Class with Static Method

Medium

Write a class MathUtils with a static method add(a, b) called on the class itself.

Input Format

A single line containing two space-separated integers.

Output Format

Print their sum.

Sample Test Cases

Sample Input 1 12 8	Sample Output 1 20
Sample Input 2 1 2	Sample Output 2 3
Sample Input 3 100 200	Sample Output 3 300

Library with List of Book Objects

Hard

Write a class Book with title and author, and a class Library with a list of Book objects and a method find(author) that prints all books by that author.

Input Format

First line: integer N. Next N lines: title and author. Last line: search author.

Output Format

Print titles of books by the search author, one per line.

Sample Test Cases

Sample Input 1 3 Python101 Guido CleanCode Robert DesignPatterns Erich	Sample Output 1 Robert
Sample Input 2 2 B1 E1 B2 E2 E1	Sample Output 2 B1
Sample Input 3 1 C1 G1 G1	Sample Output 3 C1

OOP — Employee Management

Hard

Write a class Employee with name, id, and salary, and a method yearly_salary() that returns salary * 12. Create 2 employees and print their yearly salaries.

Input Format

Two lines, each: name id salary space-separated.

Output Format

Print each employee's yearly salary on a new line.

Sample Test Cases

Sample Input 1 Alice 101 30000 Bob 102 25000	Sample Output 1 360000 300000
Sample Input 2 A 1 1000 B 2 2000	Sample Output 2 12000 24000
Sample Input 3 C 3 500	Sample Output 3 6000

OOP — Bank Transfer Between Accounts

Hard

Write a class BankAccount with balance and methods deposit(amount), withdraw(amount), and transfer(other, amount). Transfer 500 from A to B and print both balances.

Input Format

First line: initial balance of A. Second line: initial balance of B. Third line: transfer amount.

Output Format

Print 'A: [balance]' and 'B: [balance]' after transfer.

Sample Test Cases

Sample Input 1 1000 500 300	Sample Output 1 A: 700 B: 800
Sample Input 2 2000 1000 500	Sample Output 2 A: 1500 B: 1500
Sample Input 3 500 100 600	Sample Output 3 Insufficient balance

OOP — School with Student Objects

Hard

Write a class Student with name and marks, and a class School that stores students and computes average marks.

Input Format

First line: integer N. Next N lines: name and marks.

Output Format

Print the average marks rounded to 2 decimal places.

Sample Test Cases

Sample Input 1 3 Alice 80 Bob 70 Carol 90	Sample Output 1 80.00
Sample Input 2 2 A 100 B 50	Sample Output 2 75.00
Sample Input 3 3 X 10 Y 20 Z 30	Sample Output 3 20.00

Object Serialization Simulation

Hard

Write a class Record with name and value and a method to_dict() that returns {'name': ..., 'value': ...}. Read name and value and print the dict.

Input Format

First line: name. Second line: value.

Output Format

Print the dictionary representation.

Sample Test Cases

Sample Input 1 score 95	Sample Output 1 {'name': 'score', 'value': '95'}
Sample Input 2 key value	Sample Output 2 {'name': 'key', 'value': 'value'}
Sample Input 3 a 1	Sample Output 3 {'name': 'a', 'value': '1'}

OOP — Traffic Light System

Hard

Write a class TrafficLight with state and a method change() that cycles Red -> Green -> Yellow -> Red. Start at Red, call change() 4 times and print the states.

Input Format

No input.

Output Format

Print the state after each call, one per line.

Sample Test Cases

Sample Input 1	Sample Output 1 Green Yellow Red Green
Sample Input 2	Sample Output 2 Green Yellow Red Green
Sample Input 3	Sample Output 3 Green Yellow Red Green

OOP — Currency Converter

Hard

Write a class Currency with amount and a method convert(rate) that returns amount * rate.

Input Format

First line: amount. Second line: rate.

Output Format

Print the converted value rounded to 2 decimal places.

Sample Test Cases

Sample Input 1 100 74.5	Sample Output 1 7450.00
Sample Input 2 1 1	Sample Output 2 1.00
Sample Input 3 50 80	Sample Output 3 4000.00

OOP — Team with Player Objects

Hard

Write a class Player with name and runs, and a class Team that holds players and a method top_scorer() returning the player with max runs.

Input Format

First line: integer N. Next N lines: name and runs.

Output Format

Print the name of the top scorer.

Sample Test Cases

Sample Input 1 3 Sachin 100 Sehwag 80 Ganguly 60	Sample Output 1 Sachin
Sample Input 2 2 A 100 B 90	Sample Output 2 A
Sample Input 3 3 P 40 Q 60 R 80	Sample Output 3 R

OOP — Banking with Interest

Hard

Write a class Account with balance and a method apply_interest(rate) that adds rate% to the balance.

Input Format

First line: initial balance. Second line: interest rate.

Output Format

Print the balance after interest rounded to 2 decimal places.

Sample Test Cases

Sample Input 1 10000 5	Sample Output 1 10500.00
Sample Input 2 1000 10	Sample Output 2 1100.00
Sample Input 3 500 100	Sample Output 3 1000.00

OOP — Movie Catalog

Hard

Write a class Movie with title and rating, and a class Catalog that stores movies and a method best() that returns the movie with the highest rating.

Input Format

First line: integer N. Next N lines: title and rating.

Output Format

Print the title of the highest-rated movie.

Sample Test Cases

Sample Input 1 2 Inception 8.8 Titanic 7.8	Sample Output 1 Inception
Sample Input 2 1 M 9.9	Sample Output 2 M
Sample Input 3 2 A 5.5 B 9.5	Sample Output 3 B

Competitive MCQs — Class and Objects

Code snippets, output prediction, concepts & error spotting. Pick an answer to see instant feedback.

Score 0/ 39

What is the output of this code?

python

class Dog:
    def bark(self):
        print("Woof")
d = Dog()
d.bark()

Correct!

Wrong — correct answer is .

d.bark() executes the method, printing "Woof".

What is the output of this code?

python

class Car:
    def __init__(self, model):
        self.model = model
c = Car("Tesla")
print(c.model)

Correct!

Wrong — correct answer is .

The constructor stores model, accessible as c.model.

What is the output of this code?
class A:
def __init__(self):
self.x = 1
self.y = 2
a = A()
print(a.x + a.y)

Correct!

Wrong — correct answer is .

The constructor sets x=1 and y=2; their sum is 3.

How do you create an instance of class Student?

Correct!

Wrong — correct answer is .

Call the class name like a function: Student().

What does __init__ return?

Correct!

Wrong — correct answer is .

The constructor must return None; returning a value raises TypeError.

Which statement defines a class in Python?

Correct!

Wrong — correct answer is .

The class keyword defines a class, followed by a colon and block.

What is the output of this code?
class A:
count = 0
def __init__(self):
A.count += 1
a = A()
b = A()
print(A.count)

Correct!

Wrong — correct answer is .

Each construction increments the class counter, reaching 2.

What does self represent inside a method?

Correct!

Wrong — correct answer is .

self refers to the particular object the method was called on.

Which attribute lookup happens first for obj.x?

Correct!

Wrong — correct answer is .

Python checks the instance first, then its class and ancestors.

Q10

What is the output of this code?

python

class Point:
    x = 10
p = Point()
print(p.x)

Correct!

Wrong — correct answer is .

p.x looks up the class attribute x, which is 10.

Q11

What is the output of this code?
class A:
def hi(self):
return "hi"
a = A()
print(hasattr(a, "hi"))

Correct!

Wrong — correct answer is .

hasattr() returns True because the method exists on the instance/class.

Q12

Which term describes data attributes of an object?

Correct!

Wrong — correct answer is .

Values stored on an instance (via self.attr) are instance variables.

Q13

What is an attribute in Python classes?

Correct!

Wrong — correct answer is .

Attributes store state (variables) and behavior (methods) on objects.

Q14

What is the output of this code?

python

class A:
    pass
a = A()
print(type(a))

Correct!

Wrong — correct answer is .

type(a) reports the class of the object, including module: .

Q15

What is the output of this code?
class A:
def __init__(self):
self.data = []
a1 = A()
a2 = A()
a1.data.append(1)
print(a2.data)

Correct!

Wrong — correct answer is .

Each instance gets its own empty list, so a2.data is unaffected.

Q16

Can two objects of the same class have different attribute values?

Correct!

Wrong — correct answer is .

Each instance carries its own attributes; they are independent.

Q17

Which method is called automatically when you print an object?

Correct!

Wrong — correct answer is .

print() invokes __str__ if defined, otherwise falling back to __repr__.

Q18

Which special method returns a readable string for an object?

Correct!

Wrong — correct answer is .

__str__ defines what print(obj)/str(obj) shows.

Q19

What is the output of this code?
class A:
pass
a = A()
print(a.__dict__)

Correct!

Wrong — correct answer is .

An instance with no attributes has an empty __dict__.

Q20

What does __repr__ normally provide?

Correct!

Wrong — correct answer is .

__repr__ aims to be precise and useful for debugging.

Q21

What is the output of this code?
class A:
def __init__(self):
self.n = 3
def __len__(self):
return self.n
print(len(A()))

Correct!

Wrong — correct answer is .

Defining __len__ lets len() work on the object, returning 3.

Q22

Which is a class attribute?

Correct!

Wrong — correct answer is .

Class attributes are defined at class indentation level and shared.

Q23

What is the output of this code?
class A:
kind = "animal"
print(A.kind)

Correct!

Wrong — correct answer is .

Class attributes can be read directly through the class name.

Q24

What happens when you set obj.x = 5 on an instance?

Correct!

Wrong — correct answer is .

Assignment targets the instance dictionary, leaving the class attribute untouched.

Q25

What is the output of this code?
class A:
x = 1
def __init__(self):
self.x = 2
a = A()
print(A.x, a.x)

Correct!

Wrong — correct answer is .

The class keeps x=1 while the instance shadows it with x=2.

Q26

Which method is invoked when you call len(obj)?

Correct!

Wrong — correct answer is .

len() delegates to the object's __len__ method.

Q27

What is the output of this code?
class A:
def __init__(self, x):
self.x = x
print(A(5).x)

Correct!

Wrong — correct answer is .

Creating A(5) and reading .x returns 5.

Q28

What is self?

Correct!

Wrong — correct answer is .

self is automatically bound to the calling instance.

Q29

Which of these creates two independent objects?

Correct!

Wrong — correct answer is .

Calling A() twice builds two distinct instances; assignment shares one.

Q30

What is the output of this code?
class A:
pass
print(A is A)

Correct!

Wrong — correct answer is .

A class object refers to itself, so the identity check is True.

Q31

What is the output of this code?
class A:
def __init__(self, name):
self.name = name
a = A("Neo")
print(a.name.upper())

Correct!

Wrong — correct answer is .

a.name is "Neo", and upper() converts it to "NEO".

Q32

Which statement creates an object and calls its constructor?

Correct!

Wrong — correct answer is .

Calling the class with parentheses builds the object and runs __init__.

Q33

What is the output of this code?
class A:
version = 1
A.version = 2
print(A().version)

Correct!

Wrong — correct answer is .

Updating the class attribute changes what all instances see.

Q34

What is the output of this code?
class A:
pass
A.x = 100
print(A().x)

Correct!

Wrong — correct answer is .

Attributes can be added to a class at runtime and are visible to instances.

Q35

What does a method without self cause when called on an instance?

Correct!

Wrong — correct answer is .

Python passes the instance as the first argument, so a parameterless method gets too many args.

Q36

What is the output of this code?
class A:
def __init__(self):
self.values = [1, 2, 3]
print(sum(A().values))

Correct!

Wrong — correct answer is .

The instance stores the list; sum adds 1+2+3 = 6.

Q37

What is the output of this code?
class A:
x = 1
class B(A):
x = 2
print(A().x + B().x)

Correct!

Wrong — correct answer is .

A().x is 1 and B().x is 2 (overridden), summing to 3.

Q38

What does the built-in getattr(obj, "name", default) do?

Correct!

Wrong — correct answer is .

getattr safely reads an attribute with a fallback value.

Q39

What is the output of this code?
class A:
def __init__(self):
self.x = 5
print(hasattr(A(), "x"))

Correct!

Wrong — correct answer is .

The instance has x, so hasattr returns True.

Python Practice Questions

Class and Objects Practice

Competitive MCQs — Class and Objects