[DeusExMachina]

I think it's not really a chicken and egg problem though.

From a user point of view, using Python 3 looks like giving up on a lot of libraries, which in turn means a lot more work to accomplish the same things. It's a big effort that does not benefit anyone. If switching to a new version of a language makes my life harder, then I will not, especially if working on a startup or a project which is time critical.

On the other hand, this is a work that the developers of the libraries will have to do anyway, sooner or later. Doing it now would benefit a lot of people that would like to use the latest version of Python and now simply cannot afford. So why do not do it? In this case the effort would benefit a lot of people at once, which is the purpose of a library in the first place.

[garnaat]

It's a chicken/egg problem in that developers are saying I'm not porting because no one is using Python 3.x and users are saying I'm not moving to Python 3.x because none of my packages are available.

I can't just move to Python 3.x and abandon 2.x. And I have not been able to find a way to have boto support both with the same code base. So, then it becomes a matter of maintaining multiple versions of boto. Just shoot me now. If the barriers weren't so high, more packages would be running in Python3.x.

[wisty]

Yep, everyone has limited time and resources. Another problem is that many libraries have dependencies, and they can't start porting until the dependencies have been ported (or a replacement is found). Finally, library developers only want to develop for languages they like using, and who likes a language with no good libraries?

[mgkimsal]

"On the other hand, this is a work that the developers of the libraries will have to do anyway, sooner or later. "

But... will they "have to"? If a library author is waiting for 'critical adoption', they may never upgrade to Python 3 themselves, and have no need to upgrade the library, and the circle continues.

[phaylon]

It might mean they'll have to support two versions for a longer while though. Which also means making sure all community patches are provided for both branches, or manually integrating them.