class Employee:    def __init__(self, emp_id, name, salary):        self.emp_id, self.name, self.salary = emp_id, name, salary class Company:    def __init__(self):        self.staff = {}     def hire(self, emp):        self.staff[emp.emp_id] = emp     def give_raise(self, emp_id, percent):        emp = self.staff[emp_id]        emp.salary = round(emp.salary * (1 + percent / 100))     def report(self):        for e in self.staff.values():            print(f"{e.emp_id} {e.name:<6} {e.salary}") c = Company()c.hire(Employee(101, "Asha", 50000))c.hire(Employee(102, "Ravi", 62000))c.give_raise(101, 10)c.report()

101 Asha   55000
102 Ravi   62000

class Student:    def __init__(self, name, grade, marks):        self.name, self.grade, self.marks = name, grade, marks class School:    def __init__(self, name):        self.name = name        self.students = []     def admit(self, student):        self.students.append(student)     def by_grade(self, grade):        return [s.name for s in self.students if s.grade == grade]     def topper(self):        return max(self.students, key=lambda s: s.marks).name school = School("Sunrise Public School")for args in [("Asha", 5, 92), ("Ravi", 6, 81), ("Meena", 5, 88)]:    school.admit(Student(*args))print(school.by_grade(5))print("Topper:", school.topper())

['Asha', 'Meena']
Topper: Asha

class Account:    def __init__(self, balance):        self.__balance = balance     def deposit(self, amount):        if amount > 0:            self.__balance += amount     def balance(self):        return self.__balance a = Account(1000)a.deposit(500)a.deposit(-50)print(a.balance())print(hasattr(a, "__balance"))

1500
False

from abc import ABC, abstractmethod class Payment(ABC):    @abstractmethod    def pay(self, amount):        ... class UPI(Payment):    def pay(self, amount):        return f"Paid Rs {amount} by UPI" print(UPI().pay(499))try:    Payment()except TypeError as e:    print("Error:", e)

Paid Rs 499 by UPI
Error: Can't instantiate abstract class Payment without an implementation for abstract method 'pay'

class Notification:    def send(self, msg):        return f"Sending: {msg}" class EmailNotification(Notification):    def send(self, msg):        return super().send(msg) + " (via email)" print(Notification().send("Hi"))print(EmailNotification().send("Hi"))

Sending: Hi
Sending: Hi (via email)

class Calculator:    def add(self, *numbers):        return sum(numbers) c = Calculator()print(c.add(2, 3))print(c.add(2, 3, 4))print(c.add())

5
9
0

class Shape:    def describe(self):        return f"I am a {type(self).__name__}" class Square(Shape):    pass class Circle(Shape):    pass for s in [Square(), Circle()]:    print(s.describe())

I am a Square
I am a Circle

class Vehicle:    def wheels(self):        return 4 class Car(Vehicle):    def fuel(self):        return "petrol" class SportsCar(Car):    def speed(self):        return 300 s = SportsCar()print(s.wheels(), s.fuel(), s.speed())

4 petrol 300

class Camera:    def photo(self):        return "photo taken" class Phone:    def call(self):        return "calling" class SmartPhone(Camera, Phone):    pass s = SmartPhone()print(s.photo(), "|", s.call())print([c.__name__ for c in SmartPhone.__mro__])

photo taken | calling
['SmartPhone', 'Camera', 'Phone', 'object']

class Animal:    def eat(self):        return "eating" class Dog(Animal):    def bark(self):        return "barking" d = Dog()print(d.eat(), "and", d.bark())

eating and barking