This article provides a comprehensive and practical guide to implementing the Data Mapper design pattern using Python and SQLite. The pattern's role in decoupling business logic from database persistence is clearly explained, along with its benefits for scalability, maintainability, and testability. The step-by-step implementation, including setting up the database, defining the user model, and creating the UserMapper class, makes it easy to understand how to apply the Data Mapper in real-world applications.