Did we make an explicit decision to go 2.7+? 2.6 is still pretty common.

More relevantly, what bit of the code requires us to drop 2.6?

I've been only developing on 2.7+ since this past summer. Currently my main development is in Python 3 and I only run 2.7 to make sure my changes work before checking them in.

There's a number of places in codegen that use dictionary/set comprehensions and set literals, which is why it's incompatible with pre-2.7.

There's a trade off on my part between working on adding new features and having to maintain support for simultaneous versions of Python. I found that supporting three distinct versions is too cumbersome in the past for what is supposed to be experimental code.

I think that code generated by leap should be backwards compatible as far as possible. But unless there are strong indications that users may want 2.6, i would prefer to write code for newer versions.

I'd like 2.6+ as the compatibility target. For example, all the machines at NYU still use that. (CentOS...)

I'll do the cleanup sometime this week.