Low Level Design

Low Level Design (LLD) fundamental concepts Doc in Bangla

• Basics OOP Concepts
• Class and Object
• Inheritance in Object-Oriented Programming (OOP)
  • Single Inheritance
  • Multiple Inheritance
  • Method Overriding
  • ব্যাখ্যা:
• পলিমরফিজম (Polymorphism)
  • There are two main types of polymorphism:
  • Polymorphism in Python
  • Example 1: Polymorphism through Method Overriding
  • Example 2: Polymorphism with Functions
    • Example 3: Polymorphism with Inheritance
    • Advantages of Polymorphism
• এনক্যাপসুলেশন (Encapsulation)
  • Encapsulation in Python
    • Example of Encapsulation in Python
    • Explanation
• অ্যাবস্ট্রাকশন (Abstraction)
  • 1. Abstract Class:
  • 2. Abstract Method:
    • Python Implementation
    • Example in Python
    • Explanation
• SOLID Principles with Code
• Single Responsibility Principle (SRP)
  • What is SRP?
  • Benefits of SRP
  • SRP Violations
  • Python Example of SRP
    • Example: SRP Violation
  • Issues with this Code:
  • Example: SRP Adherence
  • Improvements in SRP Version:
    • Summary of SRP in Python:
• Open/Closed Principle (OCP)
  • What is the Open/Closed Principle (OCP)?
    • Benefits of OCP
  • Python Example
    • Initial Code (Violates OCP)
  • Refactored Code (Follows OCP)
    • Explanation
  • Adding a New Discount Strategy
    • Conclusion
• Liskov Substitution Principle (LSP)
  • Overview
    • Key Requirements for LSP
  • Violation Example
  • Corrected Example using LSP
    • Key Changes:
    • Benefits of LSP Compliance
• Interface Segregation Principle (ISP)
  • Overview
    • Key Concepts
  • Violation Example
    • Explanation:
  • Corrected Example using ISP
    • Key Changes:
    • Benefits of ISP Compliance
    • Conclusion
• Dependency Inversion Principle (DIP)
  • Overview
    • Key Concepts
    • Goals of DIP
  • Violation Example
    • Problems:
    • Corrected Example using DIP
    • Key Changes:
    • Benefits of DIP Compliance
    • Conclusion
• DRY Principle
  • Overview
    • Why is DRY Important?
    • Violation of DRY
  • Example 1: Refactoring Repeated Logic
    • Before (DRY Violation)
  • After (DRY Applied)
    • Key Improvements:
  • Refactoring Similar Functions with a Common Utility
    • After (DRY Applied)
    • Key Improvements:
  • Refactoring Repeated Database Operations
    • After (DRY Applied)
    • Key Improvements:
  • Avoiding Code Duplication
    • Before (DRY Violation)
    • After (DRY Applied)
    • Key Improvements:
  • Using Decorators for Cross-Cutting Concerns
    • Before (DRY Violation)
    • After (DRY Applied with Decorators)
    • Key Improvements:
• Coursera - Object-Oriented Design
  • Core Principles of Object-Oriented Design
  • Steps in Object-Oriented Design
  • Example: Designing a Library Management System
    • Step 1: Identify the Objects
    • Step 2: Define the Relationships
    • Step 3: Design Class Hierarchies
    • Step 4: Establish Object Collaboration
    • Python Implementation
    • Explanation
    • Conclusion
• KISS Low-Level Design
  • Why KISS is Important
  • Principles of KISS in Low-Level Design
  • Example: A Simple User Authentication System
    • Problem
    • Solution
    • Python Implementation
    • Explanation
    • Why is This KISS?
• YAGNI Principle (You Aren’t Gonna Need It)
  • Core Concepts of YAGNI
  • When to Apply YAGNI
  • Example: A Simple User Registration System
    • Initial Requirement: Register Users with Username and Password
    • Python Implementation
  • Explanation
  • Scenario: New Requirement - Email Verification
  • Updated Python Implementation
  • Explanation
    • Conclusion