OOP Concepts

class Student:
    pass

s1 = Student()
print(s1)

class Student:
    name = "Naveen"

s1 = Student()
print(s1.name)

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

s1 = Student("Rahul", 21)
print(s1.name, s1.age)

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

    def greet(self):
        print("Hello", self.name)

s1 = Student("Anita")
s1.greet()

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

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

r = Rectangle(10, 5)
print(r.area())

class Employee:
    def __init__(self, name, salary):
        self.name = name
        self.salary = salary

e1 = Employee("A", 30000)
e2 = Employee("B", 45000)

print(e1.name, e1.salary)
print(e2.name, e2.salary)

class Student:
    school = "KN Tech Institute"

s1 = Student()
s2 = Student()

print(s1.school)
print(s2.school)

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

s1 = Student("Ravi")
s1.name = "Ravi Kumar"
print(s1.name)

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

    @classmethod
    def from_string(cls, text):
        name, age = text.split(",")
        return cls(name, int(age))

s = Student.from_string("Priya,20")
print(s.name, s.age)

class MathTools:
    @staticmethod
    def square(n):
        return n * n

print(MathTools.square(8))

class Account:
    def __init__(self, balance):
        self._balance = balance

    def show_balance(self):
        print(self._balance)

a = Account(5000)
a.show_balance()

class Account:
    def __init__(self, pin):
        self.__pin = pin

    def verify(self, pin):
        return self.__pin == pin

a = Account(1234)
print(a.verify(1234))

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

    @property
    def age(self):
        return self._age

p = Person(25)
print(p.age)

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

    @property
    def age(self):
        return self._age

    @age.setter
    def age(self, value):
        if value < 0:
            raise ValueError("Age cannot be negative")
        self._age = value

p = Person(25)
p.age = 26
print(p.age)

class Animal:
    def eat(self):
        print("Eating")

class Dog(Animal):
    def bark(self):
        print("Barking")

d = Dog()
d.eat()
d.bark()

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

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

s = Student("Arun", "Python")
print(s.name, s.course)

class Grandparent:
    def show_a(self):
        print("Grandparent")

class Parent(Grandparent):
    def show_b(self):
        print("Parent")

class Child(Parent):
    def show_c(self):
        print("Child")

c = Child()
c.show_a()
c.show_b()
c.show_c()

class Animal:
    def eat(self):
        print("Eating")

class Dog(Animal):
    def bark(self):
        print("Bark")

class Cat(Animal):
    def meow(self):
        print("Meow")

Dog().eat()
Cat().eat()

class Father:
    def skill1(self):
        print("Driving")

class Mother:
    def skill2(self):
        print("Cooking")

class Child(Father, Mother):
    pass

c = Child()
c.skill1()
c.skill2()

class Animal:
    def sound(self):
        print("Some sound")

class Dog(Animal):
    def sound(self):
        print("Bark")

Dog().sound()

class Dog:
    def speak(self):
        print("Bark")

class Cat:
    def speak(self):
        print("Meow")

for animal in [Dog(), Cat()]:
    animal.speak()

class PDF:
    def print_file(self):
        print("Printing PDF")

class Word:
    def print_file(self):
        print("Printing Word")

def print_document(document):
    document.print_file()

print_document(PDF())
print_document(Word())

print(len("Python"))
print(len([10, 20, 30]))
print(len({"a": 1, "b": 2}))

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __add__(self, other):
        return Point(self.x + other.x, self.y + other.y)

p3 = Point(2, 3) + Point(4, 5)
print(p3.x, p3.y)

from abc import ABC, abstractmethod

class Shape(ABC):
    @abstractmethod
    def area(self):
        pass

class Square(Shape):
    def __init__(self, side):
        self.side = side

    def area(self):
        return self.side ** 2

s = Square(5)
print(s.area())

class Animal:
    pass

class Dog(Animal):
    pass

d = Dog()

print(isinstance(d, Dog))
print(isinstance(d, Animal))
print(issubclass(Dog, Animal))

class Student:
    def __init__(self, name, marks):
        self.name = name
        self.marks = marks

    def average(self):
        return sum(self.marks) / len(self.marks)

    def result(self):
        return "Pass" if self.average() >= 40 else "Fail"

s = Student("Kiran", [70, 65, 80])
print(s.name, s.average(), s.result())

class BankAccount:
    def __init__(self, owner, balance=0):
        self.owner = owner
        self.balance = balance

    def deposit(self, amount):
        self.balance += amount

    def withdraw(self, amount):
        if amount <= self.balance:
            self.balance -= amount
        else:
            print("Insufficient balance")

a = BankAccount("Naveen", 10000)
a.deposit(2000)
a.withdraw(3000)
print(a.balance)

class Employee:
    def __init__(self, name, monthly_salary):
        self.name = name
        self.monthly_salary = monthly_salary

    def annual_salary(self):
        return self.monthly_salary * 12

e = Employee("Ravi", 40000)
print(e.name, e.annual_salary())

class Engine:
    def start(self):
        print("Engine started")

class Car:
    def __init__(self):
        self.engine = Engine()

    def start(self):
        self.engine.start()
        print("Car started")

c = Car()
c.start()

class Book:
    def __init__(self, title):
        self.title = title
        self.borrowed = False

    def borrow(self):
        if not self.borrowed:
            self.borrowed = True
            print("Borrowed:", self.title)
        else:
            print("Already borrowed")

class Library:
    def __init__(self):
        self.books = []

    def add_book(self, book):
        self.books.append(book)

    def show_books(self):
        for book in self.books:
            status = "Borrowed" if book.borrowed else "Available"
            print(book.title, "-", status)

library = Library()
library.add_book(Book("Python Basics"))
library.add_book(Book("OOP in Python"))
library.books[0].borrow()
library.show_books()