A retrospective of how the community helped build Python 3.0

Abstract

In this talk I will look back at Python 3000, a large-scale effort that evolved the Python language in a discontinuous way. The result, Python 3.0, is the first Python release ever (well, at least since 1.0) to intentionally break backwards compatibility.

Rather than describing the many ways in which Python 3.0 differs from Python 2.x (whether the changes are backwards compatible or not), I'll discuss the process we developed to reach consensus on which changes to make, the considerations that went into the decision-making, the tools and documentation we produced to keep users happy, the general philosophy and strategy for getting the entire Python user and developer community to make the transition without hurting too much, and other lessons learned that will be useful for the developers of large software packages (whether open source or not).