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Category: 7. Object-Oriented Programming (OOP)

Class decorators and metaprogramming

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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

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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)

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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

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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

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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”…

Composition: “has-a” relationship

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What is Composition? Imagine you have a toy car. This toy car has different parts: wheels, a body, an engine, and so on. The toy car has wheels, it has a body, and it has an engine. This is exactly what composition is in programming. It means that one object is made up of other objects. We can use classes to represent this “has-a” relationship. Let’s look at how this works with a simple example. Example: Building a Toy Car Step 1: Creating the Parts First, let’s create the different parts of our toy car. We will create a class…

Understanding composition and inheritance

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Hey there, young coder! Today, we will learn about two important concepts in programming: composition and inheritance. Imagine you’re building with LEGO blocks. Sometimes you use different blocks together to create something cool (composition), and other times you use special blocks that inherit features from other blocks (inheritance). Let’s dive into these concepts with some fun examples using Python! Composition Composition is like putting together different LEGO blocks to build something new. In programming, it means creating complex objects by combining simpler ones. Example Let’s create a Car by combining simpler objects like Engine and Wheels. In this example: Inheritance…

Composition vs. Inheritance

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Imagine you have a toy box with different types of toys. Some toys are cars, and some toys are robots. Now, let’s say you want to create new toys that can be a combination of both cars and robots. There are two main ways to do this: Composition and Inheritance. Inheritance Inheritance is like taking a toy car and adding new features to it, like making it fly. You start with something that already exists and builds on top of it. Example: Let’s say we have a basic car and we want to create a flying car. We can use…

Implementing abstract classes

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Hey there! Today, we’re going to learn about abstract classes in Python. Imagine you’re playing with Legos, and you have different types of Lego blocks: some are square, some are round, and some are triangular. An abstract class is like a blueprint for a Lego block, but you can’t build anything with just the blueprint. You need to create specific blocks based on that blueprint. An abstract class in Python is a class that cannot be instantiated (you can’t create an object directly from it). It is meant to be a base class that other classes inherit from and provide…

Providing a blueprint for subclasses

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Sure! Let’s dive into the concept of “Providing a blueprint for subclasses” with some fun and easy-to-understand Python examples. Imagine we’re creating a special recipe book where different chefs can create their own dishes, but they all follow a basic recipe template. This template tells them what ingredients and steps they must include in their dishes, even though each dish might be different. Understanding the Blueprint Concept In programming, a blueprint is like a template that defines the basic structure for other parts of the program. In Python, we use classes to create blueprints. When we want other classes to…