[Python-Dev] Promoting Python 3 [was: PyPy 1.7 - widening the sweet spot]

[Xavier Morel]

On 2011-11-22, at 17:41 , Stephen J. Turnbull wrote:
> Barry Warsaw writes:
>> Hopefully, we're going to be making a dent in that in the next version of
>> Ubuntu.
> 
> This is still a big mess in Gentoo and MacPorts, though.  MacPorts
> hasn't done anything about ceating a transition infrastructure AFAICT.
What kind of "transition infrastructure" would it need? It's definitely
not going to replace the Apple-provided Python out of the box, so
setting `python` to a python3 is not going to happen.

It doesn't define a `python3`, so maybe that? Is there a document
somewhere on what kind of things distros need for a transition plan?

> Gentoo has its "eselect python set VERSION" stuff, but it's very
> dangerous to set to a Python 3 version, as many things go permanently
> wonky once you do.  (So far I've been able to work around problems
> this creates, but it's not much fun.)
Macports provide `port select` which I believe has the same function
(you need to install the `python_select` for it to be configured for
the Python group), the syntax is port `select --set python $VERSION`:

> python --version                                  
Python 2.6.1
> sudo port select --set python python32            
Selecting 'python32' for 'python' succeeded. 'python32' is now active.
> python --version                                  
Python 3.2.2