The Python Tutorial - Classes, Python Software Foundation, 2024 - Explains fundamental Python class definitions, objects, inheritance, and special methods.
User Guide: Custom Estimators, scikit-learn developers, 2024 - Describes how to build custom estimators and transformers conforming to scikit-learn's API, illustrating OOP principles in an ML context.
Python Cookbook, David Beazley and Brian K. Jones, 2013 (O'Reilly Media) - Provides practical recipes and solutions for advanced Python programming, including effective use of classes and objects.