[Python-Dev] Adding new features to Python 2.x (PEP 382: Namespace Packages)

[Guido van Rossum]

On Tue, Apr 7, 2009 at 5:25 AM, M.-A. Lemburg <mal at egenix.com> wrote:
> On 2009-04-06 15:21, Jesse Noller wrote:
>> On Thu, Apr 2, 2009 at 4:33 PM, M.-A. Lemburg <mal at egenix.com> wrote:
>>> On 2009-04-02 17:32, Martin v. Löwis wrote:
>>>> I propose the following PEP for inclusion to Python 3.1.
>>> Thanks for picking this up.
>>>
>>> I'd like to extend the proposal to Python 2.7 and later.
>>>
>>
>> -1 to adding it to the 2.x series. There was much discussion around
>> adding features to 2.x *and* 3.0, and the consensus seemed to *not*
>> add new features to 2.x and use those new features as carrots to help
>> lead people into 3.0.
>
> I must have missed that discussion :-)
>
> Where's the PEP pinning this down ?
>
> The Python 2.x user base is huge and the number of installed
> applications even larger.
>
> Cutting these users and application developers off of important new
> features added to Python 3 is only going to work as "carrot" for
> those developers who:
>
>  * have enough resources (time, money, manpower) to port their existing
>   application to Python 3
>
>  * can persuade their users to switch to Python 3
>
>  * don't rely much on 3rd party libraries (the bread and butter
>   of Python applications)
>
> Realistically, such a porting effort is not likely going to happen
> for any decent sized application, except perhaps a few open source
> ones.
>
> Such a policy would then translate to a dead end for Python 2.x
> based applications.

Think of the advantages though! Python 2 will finally become *stable*.
The group of users you are talking to are usually balking at the
thought of upgrading from 2.x to 2.(x+1) just as much as they might
balk at the thought of Py3k. We're finally giving them what they
really want.

Regarding calling this a dead end, we're committed to supporting 2.x
for at least five years. If that's not enough, well, it's open source,
so there's no reason why some group of rogue 2.x fans can't maintain
it indefinitely after that.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)