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Building real-world projects using OOP principles

Imagine you have a big box of LEGO bricks. Each brick is a small part, but when you put it together, you can build something amazing like a castle or a spaceship. In programming, we use something called Object-Oriented Programming (OOP) to build big projects by combining small, manageable parts. Let’s learn how to do this using Python! Real-World Project: A Simple Library System Let’s build a small library system where you can add books, lend them to people, and return them. Step 1: Define the Classes We’ll need three main classes: Library, Book, and Member. Code Example Class Definitions…

Class decorators and metaprogramming

Imagine you have a magic wand that can change how things behave without actually touching them. In Python, class decorators and metaprogramming are like that magic wand. They let us modify or enhance classes and their behavior in clever ways. Class Decorators A class decorator is a function that takes a class and returns a new class with some modifications. It’s like adding superpowers to your class without changing its original code. How to Use Class Decorators Example Let’s say we have a simple class that greets people: Here, add_super_greet is a decorator who adds a new method super_greet to…

Mixins and multiple inheritance

What are Mixins? Imagine you have a bunch of LEGO bricks. Some of these bricks can be wheels, some can be windows, and some can be doors. You can add these different pieces to your basic LEGO car to give it more functionality. Similarly, in programming, mixins are like these extra pieces. They add special features to our basic classes without being full classes themselves. What is Multiple Inheritance? Now, think of mixing different flavors of ice cream to create a new flavor. Multiple inheritance is like mixing different classes to create a new class. This new class will have…

Design patterns (Singleton, Factory, Observer)

Design patterns are like recipes in a cookbook. They show us how to solve common problems in programming in a way that has worked well for others before us. Let’s dive into some popular design patterns and understand them with simple examples in Python. 1. Singleton Pattern What is it? The Singleton pattern ensures that a class has only one instance and provides a global point of access to it. Think of it like having only one TV remote in the house. Everyone uses the same remote to control the TV. Code Example Practice Question Question: Modify the Singleton class…

Choosing between composition and inheritance

Hey there! Today we will learn about two important ways to build things in programming: composition and inheritance. Imagine you’re building with Lego bricks—sometimes you want to stick bricks together in different ways (composition), and sometimes you want to start with a big piece and add smaller pieces on top (inheritance). Let’s see how this works in Python! Inheritance Inheritance is like saying “is-a.” If a new thing is just a special kind of another thing, we use inheritance. Example: Imagine we have a basic class called Animal. Then we make a new class called Dog that inherits from Animal…

Inheritance: “is-a” relationship

Hey there! Today, we’re going to talk about a cool concept in programming called inheritance. Think of it like family traits, where kids inherit some features from their parents. In the world of programming, inheritance helps us to create new classes (like kids) that inherit properties and behaviors from existing classes (like parents). What is Inheritance? Inheritance allows us to define a new class based on an existing class. The new class (child) inherits attributes and methods (functions) from the existing class (parent). This helps us to reuse code and make our programs more organized. The “is-a” Relationship The “is-a”…