The real problem with Python 3 - no business case for conversion

[geremy condra]

On Wed, Jul 7, 2010 at 9:14 PM, Ben Finney <ben+python at benfinney.id.au> wrote:
> geremy condra <debatem1 at gmail.com> writes:
>
>> On Wed, Jul 7, 2010 at 8:26 PM, Brendan Abel <007brendan at gmail.com> wrote:
>> > Python 3.x will continue to change.  The incompatibilities between
>> > 3.x and 2.x will only become more numerous.  If your goal is to
>> > support 2.x, and 3.x, you'd be best supporting them separately.
>>
>> I maintain two projects that have to work from 2.5 to 3.1. On one of
>> them (~5kloc) we took the separate support route, and on the other
>> (~30kloc) I decided to keep a single codebase. IME the maintenance
>> burden on the former is substantially higher than the latter.
>
> The point, one more time with feeling, is that the incompatibilities
> between 2.x and 3.x will *increase* over time.

...and? I don't get to use features from 2.7, why would I expect to
use features from 3.3?

> If you now have a code base that is relatively easy to maintain for both
> Python 2.x and 3.x, that is a result of much back-porting efforts and of
> a new-feature moratorium that is currently in effect. Enjoy that
> situation as you may, because it is guaranteed not to last.

I have to target the oldest version of Python I want to support. New
features are irrelevant. I'm not sure why I should need to explain
that to you.

> Indeed, the feature moratorium is designed in part to help slow-moving
> codebases migrate to Python 3.x before Python resumes its normal pace of
> change again. If you're choosing to use that time to further entrench
> codebases for Python 2.x, I think that's a short-sighted choice.

I welcome the day that I can stop supporting 2.x. Until then, I have to
support both and your argument is irrelevant.

> Python 2.7 is the last 2.x, no further 3.x features will be back-ported.
> New 3.x features will begin to appear after the moratorium ends. The
> combination of those two means that *the single-codebase burden will
> only increase over time* as Python 3.x diverges further from what Python
> 2.x can support.

See above.

Geremy Condra