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Day 19: Introduction to Object-Oriented Programming (OOP)

Object-Oriented Programming is a programming paradigm that uses objects to represent real-world entities.

  • Classes and Objects:
    • Classes define blueprints for creating objects.
    • Objects are instances of classes.
  • Attributes and Methods:
    • Classes can have attributes (data) and methods (functions) that define their properties and behavior.

Example of creating a simple class and an object:

# Define a simple class
class Dog:
    def __init__(self, name):
        self.name = name

    def bark(self):
        print(f"{self.name} says woof!")

# Create an object (instance) of the Dog class
my_dog = Dog("Buddy")
my_dog.bark()  # Call the bark method on the object

Day 20: Class Attributes and Methods

Classes can have attributes and methods that define their behavior.

  • Class Attributes:
    • Class attributes are shared among all instances of the class.
  • Instance Attributes:
    • Instance attributes are specific to individual objects.
  • Methods:
    • Methods are functions defined within a class.

Example of class attributes and methods:

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

    def area(self):
        return 3.14159 * self.radius**2

    def circumference(self):
        return 2 * 3.14159 * self.radius

my_circle = Circle(5)
print(f"Area: {my_circle.area()}")
print(f"Circumference: {my_circle.circumference()}")

Day 21: Inheritance

Inheritance allows you to create new classes that inherit attributes and methods from existing classes.

  • Parent Class (Superclass):
    • The parent class defines common attributes and methods.
  • Child Class (Subclass):
    • The child class inherits from the parent class and can have additional attributes and methods.

Example of inheritance:

# Parent class
class Animal:
    def __init__(self, name):
        self.name = name

    def speak(self):
        pass

# Child class inheriting from Animal
class Dog(Animal):
    def speak(self):
        return f"{self.name} says woof!"

my_dog = Dog("Buddy")
print(my_dog.speak())  # Calls the speak method of the Dog class

Day 22: Polymorphism

Polymorphism allows objects of different classes to be treated as objects of a common superclass.

  • Common Superclass:
    • Create a common superclass that defines shared methods or attributes.
  • Subclasses with Different Implementations:
    • Subclasses provide their own implementations of methods.

Example of polymorphism:

# Common superclass
class Shape:
    def area(self):
        pass

# Subclasses with different implementations of area
class Circle(Shape):
    def __init__(self, radius):
        self.radius = radius

    def area(self):
        return 3.14159 * self.radius**2

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

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

shapes = [Circle(5), Rectangle(4, 6)]

for shape in shapes:
    print(f"Area: {shape.area()}")

Object-Oriented Programming (OOP) is a fundamental concept in Python and many other programming languages. It allows you to model real-world entities, promote code organization, and enhance code reusability. Practice with these examples to become proficient in using OOP principles in Python.