[PyQt] Re: PyQt4 and Python 3.0

[Arthur Pemberton]

On Mon, Oct 6, 2008 at 7:33 PM, Doug Bell <dougb at bellz.org> wrote:
> Giovanni Bajo wrote:
>> On 10/6/2008 7:27 PM, Joshua Kugler wrote:
>>> Phil Thompson wrote:
>>>
>>>> On Fri, 3 Oct 2008 17:11:19 +0200, Detlev Offenbach
>>>> <detlev at die-offenbachs.de> wrote:
>>>>> Hi,
>>>>>
>>>>> will there be PyQt4 support for Python 3.0 once it goes final?
>>>> Not straight away. I will take the opportunity to break backwards
>>>> compatibility (eg. removing QVariant, QString, QChar, QByteArray etc), and
>>>> those changes will be made over a period of time. So it may be a while
>>>> before the API is stable enough for anything other than playing.
>>>
>>> Before you do that, please take into consideration Guido's advice:
>>>
>>> "Don't change your APIs incompatibly when porting to Py3k."
>>>
>>> http://www.artima.com/weblogs/viewpost.jsp?thread=227041
>>
>> I think the main collision here is that Guido is trying to help people
>> porting their applications to Python 3.0, while Phil seems to think that
>> it's better to rewrite them.
>>
>> IMO, PyQt shouldn't force its users to rewrite their code, especially
>> *not* tieing this to someone else's schedule (Qt4 release, Python 3
>> release). If an application grows unmaintainable, it will get eventually
>> rewritten but only when the programmer thinks so.
>>
>> Putting incompatible changes into PyQt and then telling people "*now*
>> it's time to rewrite" doesn't seem a good path forward to me.
>>
>> If there's agreement that we need to break backward compatibility on
>> PyQt (by changing the way QString or QVariant are mapped), I think it's
>> better to do so *independently* from any other changes (eg: Python 3).
>
> I disagree, for several reasons:
>
>  - Doing the changes separately means maintaining three separate
>    versions of PyQt at once, taking more of Phil's time and promoting
>    confusion.
>
>  - Many Linux distros are unlikely to support all three versions at
>    once.
>
>  - The QString changes are somewhat related to Python 3's unicode
>    string changes.  Both changes would affect the same portions of
>    application code.
>
>  - I agree that porting an application with both sets of changes is
>    tougher than doing one change alone, but it's still easier to
>    thoroughly test my applications once, rather than twice.


My humble opinion:

Take some time with the community, collect opinion on all the bad
parts of PyQt, and then make a clean break to rewrite PyQt4 for Python
2.6, making use of future features whenever possible.

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