Noob in Python. Problem with fairly simple test case

[Chris Angelico]

On Fri, Jul 17, 2015 at 4:47 PM, Steven D'Aprano <steve at pearwood.info> wrote:
>> Jessie's default should be 2.7, at least. Wheezy shipped 2.7, too;
>> it's only Squeeze (now out of support) that didn't ship any 2.7.x
>> Python. Are you sure you can't at least upgrade to 2.7?
>
> I'm not sure, I'm not actively involved in that specific project. All I know
> is that the guys are always complaining about Jessie, and that they're
> using 2.6.

Huh. Then maybe it's the other way: Jessie no longer ships or supports
2.6, so if 2.7 breaks the code, then so will Jessie. But I'm looking
over the 2.7 What's New page, and it honestly doesn't jump out at me
screaming "Your code will break!". Strange.

Anyway, the specifics don't matter. What matters is that there *are*
people who are using the system-provided Python, and that (so far)
that's Py2 for the majority of Linux distros. But that's definitely
changing; Ubuntu and Debian are both aiming toward a state of "ship
Python 3 by default, but if you want 2.7, you'll have to download it",
which implies that all system scripts will be ported to 3.x. Once that
happens, I expect that all Debian-derived distros will follow pretty
quickly (it's easy to transition if someone else has already done the
vast majority of the work, by which I clearly mean about 87.4%), and
non-Debian distros can probably take advantage of the prior work too,
to some extent. That'll shift the balance on Linux from "mostly Py2"
to "mostly Py3", and that'll have knock-on effects on Windows and Mac
OS too, as third-party script developers will find it advisable [1] to
write their code to match the predominantly available version.

> My guess is, the rate of Python 3 adoption is going to hit the tipping point
> in 2 or 3 years, after which time it will be *very* rapid.

Yep, I'd agree with that estimate. Debian Stretch (9) may or may not
switch; I'd be very surprised if Debian Buster (10) didn't have Py3 by
default.

ChrisA

[1] The question is, what did the archbishop find?