The Hitchhiker's Guide to Python

Chapter 4. Writing Great Code

This chapter focuses on best practices for writing great Python code. We will review coding style conventions that will be used in Chapter 5, and briefly cover logging best practices, plus list a few of the major differences between available open source licenses. All of this is intended to help you write code that is easy for us, your community, to use and extend.

Code Style

Pythonistas (veteran Python developers) celebrate having a language so accessible that people who have never programmed can still understand what a Python program does when they read its source code. Readability is at the heart of Python’s design, following the recognition that code is read much more often than it is written.

One reason Python code can be easily understood is its relatively complete set of code style guidelines (collected in the two Python Enhancement Proposals PEP 20 and PEP 8, described in the next few pages) and “Pythonic” idioms. When a Pythonista points to portions of code and says they are not “Pythonic,” it usually means that those lines of code do not follow the common guidelines and fail to express the intent in what is considered the most readable way. Of course, “a foolish consistency is the hobgoblin of little minds.”¹ Pedantic devotion to the letter of the PEP can undermine readability and understandability.

PEP 8

PEP 8 is the de facto code style guide for Python. It covers naming conventions, code layout, whitespace (tabs versus spaces), and other ...