[hacman]

I have heard Stroustrup speak and he mentioned multiple times how important it is to maintain compatibility with all existing code in between language versions. Say what you want about C++, but I think they have the right approach. If you are the steward of such a fundamental project, it is definitely in your users' (and therefore your project's) best interest to keep everything that exists working. It's just not worth the pain to make trivial changes in the name of aesthetics or "usability" that break every single hello world program (making print a function instead of a statement) or to change how the division operator works for your millions of existing users to save some initial confusion for hypothetical potential users.

C++ may have become a bit unwieldy as a result of the combination of this policy and the focus on adding new features, but developers working on existing code bases can continue to develop happily ignoring as much of C++11 as they like without the concern that the plug will be pulled in their platform some time soon. As they decide to adopt the new features, they can, based in the merits of the feature, not because they are forced to by the platform's developers.

There are starting to be some compelling features in py3k, but none of those required the massive language breakage that has happened between Python 2.x and these releases. All of the compelling features could have been added piecemeal through the normal backward-compatible deprecation and release process. And the devs who were so bothered by print and exec being a function, or other stupid things could continue to complain in the mailing list while the rest of us get our work done.

[deong]

I tried very hard to be in the python3 camp. I'm among those who found the changes to be mostly good ones, and I've talked myself into biting the bullet a couple of different times, but it always turns out the same.

Last month I gave up and reverted the project I'm working on now back to python2 after spending an afternoon looking for unofficial ports of a large library only to find that someone on Github had forked it, done the hard work of fixing 2200 broken bits, and had his pull request ignored without comment for a full year.

I give up.

[garenp]

Which library is that? Truly curious.

[deong]

Pybrain.

Apparently it's sort of unmaintained in general, but I was trying to use it for something that I wasn't happy with scikit-learn for, and at the time, I wasn't aware of how long it had been since it had been updated in general.

So in hindsight, it wasn't the best example, but I had already had to deal with tracking down an random person's networkx branch as well, so that was enough to make me finally just fix the few things needed to work in 2.7.

[rspeer]

I think you'll have an increasingly hard time finding good examples. Most packages that aren't ready for Python 3 by now are just unmaintained. At best they're so bogged down in their own complexity that you should be wary of using them for anything new.

Sometimes you need to use unmaintained or legacy code, and that sucks. But there are lots of programmers who don't have such a burden, and they shouldn't be discouraged from Python 3.

networkx is Python 3 compatible, by the way.

[deong]

> networkx is Python 3 compatible, by the way.

So it is. I'm not sure why I couldn't find that six months ago while I was looking.

Also, I don't mean to imply that people should be discouraged from using Python 3. Like I said, I want to use it myself, and would be if I hadn't ran into problems.