Descriptors and Metaclasses: Adding Super Powers Python Classes

Satyam Soni (~satyamsoni2211)




Supercharging Python Classes with Descriptors and Metaclasses

In the world of Python programming, classes are powerful tools that allow us to encapsulate data and functionality into neat and reusable structures. However, there are times when we want to enhance the capabilities of our classes and imbue them with extraordinary abilities.

That's where descriptors and metaclasses come in. Descriptors provide a powerful mechanism for controlling and customizing attribute access in Python classes, while metaclasses allow us to modify class behavior itself at the time of class creation. Together, they offer a robust toolkit for crafting sophisticated and flexible Python code.

Workshop Overview

In this workshop, we will dive deep into the world of descriptors and metaclasses, exploring how they can empower our classes with superpowers. We will begin by understanding the fundamental concepts of descriptors and metaclasses and how they fit into the overall Python class model.


Descriptors allow us to define the behavior of attribute access, such as getting, setting, and deleting values, by intercepting the corresponding operations. We will explore various types of descriptors, including data descriptors, non-data descriptors, and get-only descriptors, each serving different purposes.

Topics to be Covered

  • Descriptors Introduction
    • Understanding the Descriptor Protocol
    • How Descriptors Fit into Python's Class Model
  • Applications of Descriptors
    • Validations
    • Data Transformation
    • Data Attributes
    • property Getter and Setter Methods
    • Many More Practical Use Cases
  • Types of Descriptors and Deep Dive
    • Data Descriptors
    • Non-Data Descriptors
    • Descriptor Methods: __get__, __set__, __delete__
    • Descriptor __set_name__ Hook
  • Live Hands-On with Descriptors
    • Implementing Data Descriptors
    • Implementing Non-Data Descriptors
    • Using Descriptors as Validators
    • Creating Computed Properties with property
    • Lazy Loading with Descriptors
    • Descriptors in Libraries like SQLAlchemy, Django ORM


Metaclasses are a way to customize class creation in Python. They allow us to modify the behavior of classes themselves, giving us the power to enforce rules, add methods or properties, and even alter inheritance.

Topics to be Covered

  • Metaclasses Introduction
    • What is a Metaclass?
    • How Metaclasses Work
    • The type Metaclass
  • Applications of Metaclasses
    • Enforcing Coding Standards
    • Automatic Registration of Classes
    • Singleton Pattern Implementation
    • Class Decorators
  • Metaclass Methods and Deep Dive
    • Customizing Class Creation with __new__ and __init__
    • Metaclass __prepare__ Method
    • Practical Examples and Use Cases
  • Live Hands-On with Metaclasses
    • Creating and Using Simple Metaclasses
    • Advanced Metaclass Techniques
    • Combining Metaclasses with Descriptors
    • Real-World Examples and Libraries

Putting It All Together

We will integrate our understanding of descriptors and metaclasses, demonstrating how they can work together to create powerful and flexible Python classes. This section will include advanced examples and real-world scenarios where both descriptors and metaclasses are used to achieve sophisticated class behaviors.


By the end of this workshop, you will have a solid understanding of how descriptors and metaclasses work, and how to leverage them to unlock new possibilities in your Python classes. Whether you are a beginner seeking to expand your Python knowledge or an experienced developer looking to level up your class design skills, this workshop will provide valuable insights and hands-on experience.

So, join me on this exciting journey as we delve into the world of descriptors and metaclasses and unlock the superpowers of Python classes. Let's elevate our programming skills and discover new dimensions of class design together. Get ready to add superpowers to your code!


  • Python3 (>=3.9)
    • Editor of Choice ( VSCode Preferred, PyCharm )
    • Poetry ( Dependency Management )

Speaker Info:

A Python Enthusiast with over 7 years of experience working across multiple domains, verticals, and Frameworks. I am an active Open-Source contributor, with multiple libraries published over PyPI (lazy-alchemy, py-lambda-warmer, flask-dantic etc.), and currently working as Technology Lead with SenecaGlobal, delivering Python Based Full Stack Solutions.

Section: Core Python
Type: Workshops
Target Audience: Advanced
Last Updated: