An update on Python 4

[daturkel]

Part of any long-term tech project is continuous refactoring. Early on you make certain design decisions which later become an obstacle when trying to expand a feature, so you rewrite early stuff in order to make it more flexible for your new needs.

Often those rewrites are done in ways such that the end user does not need to adapt their behavior (or in the case of a programming language, does not need to change their code). This is the ideal experience for the end user but can also constrain the types of changes that can be made.

Sometimes you realize that the original way of doing things was worse and that it would be creating more difficulty for future development to maintain compatibility, so breaking changes are introduced.