Pandas User Guide: Group by: split-apply-combine, pandas development team, 2023 - This official documentation provides a detailed explanation and examples of Pandas groupby operations and aggregation functions.
Python for Data Analysis, Wes McKinney, 2022 (O'Reilly Media) - Written by the creator of Pandas, this book is a definitive guide to data manipulation in Python, with dedicated sections on groupby and aggregation (3rd edition).
Effective Pandas: Powerful Tools for Data Manipulation, Matt Harrison, 2021 (O'Reilly Media) - This practical guide offers clear explanations and examples for efficient data aggregation and manipulation using Pandas groupby.