PEP 8 -- Style Guide for Python Code, Guido van Rossum, Barry Warsaw, and Alyssa Coghlan, 2001 - Official style guide for Python, establishing conventions for code consistency, including naming and formatting.
Clean Code: A Handbook of Agile Software Craftsmanship, Robert C. Martin, 2008 (Prentice Hall) - A seminal work on software craftsmanship, offering principles for writing clean, readable, and maintainable code, especially regarding effective function design.
Effective Python: 90 Specific Ways to Write Better Python, Brett Slatkin, 2019 (Addison-Wesley Professional) - Offers practical advice and Pythonic best practices for writing robust, efficient, and idiomatic Python code, including guidance on functions, modules, and type hinting.
The Python Tutorial - Modules, Python Software Foundation, 2023 - Official Python documentation explaining the concepts of modules and packages, their creation, import mechanisms, and organization.