[Linux-SIG] Updating PEP 394 to recommend soft-linking python to python3 on newer distributions

[Petr Viktorin]

On 9/26/18 12:19 PM, Nick Coghlan wrote:
> On Wed, 26 Sep 2018 at 00:49, Barry Warsaw <barry at python.org> wrote:
>>
>> On Sep 24, 2018, at 05:48, Sorin Sbarnea <ssbarnea at redhat.com> wrote:
>>>
>>> I would like to propose a change on PEP 394 recommendations which were originally made almost 7 years ago when python3 was bleeding edge for most distributions.
>>
>> The last time this topic came up, we essentially deferred changing PEP 394 until after Python 2’s official EOL date.  I think that’s still appropriate.  Once Python 2 is for good and ever retired, then it’s worth considering changes to PEP 394’s language.
> 
> Yep, this is still where Fedora is at as well - step 1 is to eliminate
> legacy references to the python symlink, and then step 2 will be to
> figure out if/when it ever comes back as a way of referring to a
> generic version of Python.

Actually, step 1 is done, minus stragglers that are hard to find and 
won't switch until things break for them.
I would be fine switching "python" to Python 3 in Fedora 30 (which is 
being developed now, and will be supported into 2020), but only if we 
agree it's the thing to do -- and I consider PEP 394 to be the place for 
core dev consensus.

> Personally, I suspect it's more likely that we''ll start shipping
> https://github.com/brettcannon/python-launcher with CPython at some
> point, similar to the way we ship the original py launcher for
> Windows.

I have doubts that would help. Until `py` is everywhere, you'll still 
have different ways to start Python on different systems, and `py -3` 
vs. `python3` is, frankly, not much of a difference.