the Gravity of Python 2

[Chris Angelico]

On Thu, Jan 9, 2014 at 2:06 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2014-01-08, Chris Angelico <rosuav at gmail.com> wrote:
>
>> Two reasons for moving:
>>
>> 1) Support for newer hardware
>
> How does Python 3.x support newer hardware than Python 2.7?

At the moment, I would say there's no difference between those two
versions. But there was an issue a short while ago about OS X 10.9 and
the compilers/libraries available for it, which necessitated some
patches, and those patches would have been applied to all
currently-supported versions of Python. That means that 2.7 got them
(in 2.7.6 [1]), so it'll build nicely, but 2.6 won't have, so anyone
who wants to use 2.6 on 10.9 will have to manually backport that fix.
I mention hardware because there are times when the new hardware won't
run the old OS, the new OS won't work with the old compiler and/or
library, and the new compiler/library won't work with the old Python.
At that point, you have to either run a virtual machine (overkill) or
remain on the old hardware (hence, Python X.Y doesn't support your
hardware).

So long as 2.7 is being supported, there are no problems with this.
Same with the bug fixes and security patches that I mention in the
next line. Once it's out of support, though, both will cease (or they
might cease at different times), and then new hardware, new compilers,
new versions of required libraries, could cause problems. I elaborated
further down that these issues would be mainly dealt with by OS
package maintainers (I'm sure Red Hat have been doing this for years),
but they'll still be problems.

[1] http://www.python.org/download/releases/2.7.6/

ChrisA