[Python-ideas] Make py.exe default to Python 3

[Steve Dower]

On 08Mar2016 1334, Alexander Walters wrote:
>
> On 3/8/2016 16:29, Ian Kelly wrote:
>> On Tue, Mar 8, 2016 at 2:17 PM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>> On 03/08/2016 01:11 PM, Alexander Walters wrote:
>>>
>>>> -1 py.exe should use whatever was first installed by default.  If
>>>> that's
>>>> 2.7, then it's 2.7.  if its python 9.9, then its python 9.9. but it
>>>> should use whatever was FIRST installed unless the user changes it.
>>>
>>> Which is still asking for a change from what happens now; i.e. if 3.3 is
>>> installed first, then 2.7, py.exe will default to 2.7.
>>>
>>> I agree whichever is first installed should be default; I also think
>>> installer should have an option to change the py.exe default to the
>>> version
>>> being installed.
>> It would also be nice to have a way to change the default without
>> needing to rerun an installer.
> I am all for more configuration ex post facto.  We are talking about the
> tyranny of the default though, which is complicated by the fact that it
> wont see the light of day until 3.6 (unless we backport a modified
> version of py.exe in future releases of 2.7 and 3.*).

"First installed" is a very difficult proposition, especially if you 
want versions of Python pre-3.6 to participate. "Last installed" is 
slightly better, though not easy to do without triggering systems that 
detect corrupted installations.

Personally I think "latest version" is the best default (compared to the 
current "latest 2.x version"), so I'm +1 on removing the assumption that 
"PY_PYTHON" is "2" by default.

Users can change their own default with any of the mechanisms described 
at https://docs.python.org/3/using/windows.html#customization

Cheers,
Steve