[avdd_]

> I'll start with the conclusion: making backwards incompatible version of a language is a terrible idea, and it was bad a mistake.

> So let me fix that: I do recommend a single code base as the solution.

> The original advice to think very separately about your 2.x and 3.x codebases was very wrong, has wasted a ton of time (since you end up porting to python 3 twice), and overall slowed down the adoption of py3k, a slowdown that fortunately is finally lifting.

Is this opinion common? Do Guido and the other core developers admit they were wrong?

> Python 3.0 will break backwards compatibility. Totally. We're not even aiming for a specific common subset.

That a single code base is now possible, albeit "not entirely idiomatic", does support the conclusion that the original aim to break compatibility was misguided at best, and raises questions about the governance of Python overall.

[avdd_]

Well zed seems to agree

https://twitter.com/zedshaw/status/364118939233554432

> they've been keeping this "dual mode" option mostly a secret so as to not have to admit they fucked up

[tshepang]

If this is not a joke, Zed is paranoid.

[tshepang]

If 'raises questions about governance' means the leadership can't predict the future, then I agree. Else, this is not fair, since features were added to Python 2.6 to reduce migration pain (which incidentally enabled this single-codebase thing possible).