Pandas User Guide: Indexing and selecting data, The Pandas Development Team, 2024 - Provides authoritative guidance on selecting columns and filtering rows using various Pandas methods, including boolean indexing.
Pandas User Guide: Working with missing data, The Pandas Development Team, 2024 - Details how to identify and handle missing values in DataFrames, specifically covering the dropna() method used for data preparation.
Python for Data Analysis, Wes McKinney, 2022 (O'Reilly Media) - The definitive book on data manipulation with Pandas, covering data selection, filtering, and missing data handling comprehensively. (3rd edition)