Encapsulation & Properties

Encapsulation is one of the core principles of OOP. It means hiding the internal details of a class and controlling access to data.

Why Encapsulation?

Without encapsulation, anyone can modify your data in unexpected ways:

Private Attributes: _ and __

Python uses naming conventions to indicate "privacy":

• Single underscore _: "Internal use" (convention, not enforced)
• Double underscore __: Name mangling (stronger privacy)

Name Mangling with __

Double underscore triggers name mangling - Python renames the attribute to make it harder to access.

The @property Decorator 🎯

Properties let you use method calls like attributes. This is the Pythonic way to implement getters and setters.

Read-Only Properties

Omit the @setter to create a read-only property.

Validation with Properties

Properties are perfect for validating data before storing it.

Coding Challenge: Temperature Class 🌡️

Create a Temperature class with Celsius and Fahrenheit properties that auto-convert.

Quiz

Key Takeaways

✅ Encapsulation hides internal details and controls access.
✅ _attribute is a convention for "internal use".
✅ __attribute triggers name mangling for stronger privacy.
✅ @property creates getters (access like attributes).
✅ @setter validates data before storing.
✅ Read-only properties omit the setter.

What's Next?

In the next lesson, we'll learn about Inheritance & Polymorphism - how to create class hierarchies and reuse code.

Keep coding! 🚀