Python, for all its power and popularity, has long lacked a form of flow control found in other languages—a way to take a value and match it elegantly against one of a number of possible conditions.

You may know The Pattern as that astrology app that flabbergasted Channing Tatum over its accuracy, or perhaps you use it for zodiac-based daily updates on your personality and feelings like I do. But ...

A person opens an app, fills out a profile, and waits. Somewhere in a server farm, code runs through millions of data points. It compares answers to questions, analyzes swiping patterns, and weighs ...