Mixin classes

Definition

Mixin classes are a type of class used to provide optional features to other classes through multiple inheritance. They are designed specifically for adding methods and properties to other classes without being intended for standalone instantiation.

5 Must Know Facts For Your Next Test

1. Mixin classes allow the reuse of code across different classes without forming a rigid hierarchy.
2. They enable multiple inheritance by allowing a class to inherit methods and attributes from more than one parent class.
3. A mixin should ideally only implement a small set of related functionalities, keeping them modular.
4. In Python, mixins are commonly used to add utility methods or shared functionality to different classes.
5. When using mixins, method resolution order (MRO) is vital as it determines which method is called when there are multiple inheritance paths.

Review Questions

• What is the primary purpose of a mixin class in Python?
• How does using mixin classes facilitate code reuse?
• What role does the method resolution order (MRO) play in the context of mixin classes?

Related terms

Multiple Inheritance:

A feature in object-oriented programming where a class can inherit behaviors and attributes from more than one parent class.

Method Resolution Order (MRO):

The order in which base classes are searched when executing a method. It becomes especially important with multiple inheritance.

Composition:

A design principle where one class contains an object of another class, allowing complex functionalities without using inheritance.