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

[Paul Moore]

On 8 March 2016 at 11:22, Victor Stinner <victor.stinner at gmail.com> wrote:
> 2016-03-08 10:24 GMT+01:00 Paul Moore <p.f.moore at gmail.com>:
>> The "py.exe" wrapper on Windows runs the latest Python version
>> available on the user's PC, but it prefers Python 2 if the user has
>> both Python 2 and 3 installed. With Python 3.5 being released, is it
>> not about time that we switched that default to always prefer the
>> latest version available?
>
> On UNIX, it was decided to have python2 and python3 and don't guess
> user expectations.
>
> Why not providing an py3 runner which uses Python 3 by default?

I don't know. Personally, I don't like the versioned executables (will
we get a py4, py5,...?) but that's just a personal preference.

I believe that with an unversioned executable it should use the latest
version by default, and the point of my email is that I think we're
now at a point where special casing Python 2 is unreasonable,
particularly on Windows where there is no tradition of a "system
Python" which needs to be Python 2. If someone *else* wants to propose
replacing py.exe with py2.exe and py3.exe then they can do that (and
I'll be -1 on that proposal).

You don't mention the fact that an unadorned "python" command on Unix
typically invokes Python 2. As far as I know the only reason that was
needed was because system Python scripts were written that way, back
before Python 3 was around, and couldn't be updated to be Python 3
compatible. That reason doesn't apply on Windows. And on Windows,
"python" has always referred to the currently active version of
Python, whether 2 or 3.

tl; dr; I'm against making the unversioned name "python" (or "py")
forever mean Python 2. There are justifications for it on Unix, but
none of those apply on Windows.

Paul