Class Methods & Static Methods

Python has three types of methods: instance methods, class methods, and static methods. Each serves a different purpose.

Method Types Comparison

Instance Methods (Review)

These are the regular methods you've been using. They receive self and can access instance attributes.

Class Methods: @classmethod 🏭

Class methods receive the class itself as the first parameter (cls), not an instance.

Use cases:

• Factory methods (alternative constructors)
• Modify class state
• Access class variables

Static Methods: @staticmethod 🔧

Static methods don't receive self or cls. They're just regular functions that belong to the class namespace.

Use cases:

• Utility functions related to the class
• Functions that don't need instance or class data

Factory Pattern with Class Methods 🏭

Class methods are perfect for creating alternative constructors.

When to Use Each Type 🤔

Coding Challenge: Employee Management System 👔

Create an Employee class with all three method types.

Quiz

Key Takeaways

✅ Instance methods use self and access instance data.
✅ Class methods use @classmethod and cls for class-level operations.
✅ Static methods use @staticmethod for utility functions.
✅ Factory pattern uses class methods for alternative constructors.
✅ Choose based on what data you need to access.

What's Next?

In the next lesson, we'll do a Decorators Deep Dive - creating custom decorators and understanding how they work.

Keep coding! 🚀