[Python-Dev] PEP 414 - Unicode Literals for Python 3

[Terry Reedy]

On 2/28/2012 7:10 AM, Vinay Sajip wrote:

> The PEP 314 approach seems to assume that that if things work on 3.3,
> they will work on 3.2/3.1/3.0 without any changes other than
> replacing u'xxx' with 'xxx'.

(Delete 3.0. 3.1 is also less of a concern.) It actually assumes that if 
things work on 3.3 *and* 2.7 (or .6), then ... . At first glance, this 
seems reasonable. If the code works on 2.7, then
it does not use any new 3.3 features. Nor does it depend on any 3.3-only 
bug fixes that were part of a feature patch. 2.6, of course, is 
essentially not getting any bugfixes.

> In other words, you aren't supposed to want to e.g. test 3.2 and 3.3
> iteratively, using a workflow which intersperses edits with running
> tests using 3.2 and running tests with 3.3.

Anyone who is also targeting 3.2 could run a test32 script whenever they 
need to take a break. Or it could be run in the background (perhaps on a 
different core) while editing continues. People will work this out on a 
project by project basis, or use one of the other solutions.

> In any case, a single code base seems not to be possible across
> 2.6+/3.0/3.1/3.2/3.3+ using the PEP 314 approach, though of course
> one will be possible for just 2.6+/3.3+. Early adopters of 3.x seem
> to be penalised by this approach: I for one will try to use the
> unicode_literals approach wherever I can.

Early adoption of new tech typically has costs as well as benefits ;-).

-- 
Terry Jan Reedy