Classy Abstractions

Let’s talk about abstractions and Pythonic code.

So far, I’ve held it at Python Web Conf 2020 and Python Conference 2021 in the Zoo of Amersfoort / Netherlands.

• Primitive Obsession
• Overcoming Primitive Obsession uses Ruby but the same principles apply.
• Premature Optimization
• Donald Knuth is never shy of a pithy quote.
• Fixing Unix/Linux/POSIX Filenames: Control Characters (such as Newline), Leading Dashes, and Other Problems 30,000 words on UNIX filenames.
• pathlib
• ipaddress
• yarl is my favorite URL library.
  • hyperlink is cool too and comes from the Twisted ecosystem.
• JSON:API a specification for building APIs in JSON.
• Flask for Fun and Profit by Armin Ronacher.
• voluptuous, despite its name, remains my favorite data validation package for Python.
• Finite-state machines are an abstraction that allows to declare states, valid inputs, and transitions based on them. They usually replace huge and brittle if-then-else trees.
  • Automat is a production-ready implementation of that concept.
• Simple Made Easy by the creator of Clojure. A seminal talk on the difference between simple and easy solutions.
• decimal is a decent type for money.
• How to pronounce “__”? (2002)
• Stop Writing Classes
  • Start Writing More Classes
  • Stop writing stupid classes. (aka The controller pattern is awful (and other OO heresy))
• 99 Bottles of OOP is my favorite book on class design, albeit it uses Ruby.
  • Everything by Sandi Metz is great for that matter (scroll down for her talks).
• Architecture Patterns with Python, the most important Python book of the past years. You should read it.
  • I have written many words on subclassing that is relevant: Subclassing in Python Redux. Brew yourself a hot beverage and enjoy the ride!
• characteristic was my first terrible attempt at writing a class creator – for historical interest only.
• attrs
• dataclasses
  • Fun with PEPs

Credits

• Turnstile FSM adapted from Wikipedia
• Turnstile photo