On Fri, 03 Oct 2008 16:45:12 -0700, Glenn Linderman <[EMAIL PROTECTED]> wrote: > On approximately 10/3/2008 4:25 PM, came the following characters from > the keyboard of Phil Thompson: >> Personally I think "compatibility wrappers" are a waste of time and >> effort. >> There are times when you really should rewrite your application (and I >> don't care how big it is). PyQt4 is a complete rewrite of PyQt3, SIP5 >> will >> not share any code with SIP4. >> > > Interesting philosophy. Some truth there. But then it is a big job to > do a rewrite, and someone else's release schedule isn't always the right > time.
You have a potential problem if one customer wants your app for Py2 and another for Py3. In reality I don't see that as a major problem as paying customers are going to be the most conservative. I think it will be a while before Py3 becomes mainstream. >> Major transitions (Qt3 => Qt4, Python2 => Python3) should be considered >> as >> opportunities for rewrites. They should not be treated as "how can I get >> from one to the other with as few changes as possible". >> > > If the application was old, I might agree. But here I am, thinking > about, and starting to code, a brand new application. > >> Therefore, to answer your specific question, if you need to deploy your >> application within 6 months (as a minimum) then write for Python2. If you >> do then don't bother trying to write it with Python3 in mind. By the time >> you get to the point when you want a Python3 version you will have >> realised >> how badly you wrote it in the first place that you will want to rewrite >> it >> anyway. >> > > So say I wish to deploy in 8 months (the reality is, it will be deployed > when it is ready, if not sooner, and that depends on how things go with > some other projects also)... I'd like to avoid deploying it twice in > succession on different platforms within a couple months... and even if > it was deployed in 4 months, I'd hardly know what to rewrite by then. Unless your have specific customer demands as I mentioned above, then its up to you what you deploy. >> On the other hand, if you did write it correctly in the first place >> (something I've never managed) PyQt4 for Python2 will be maintained for >> several years - certainly while new versions of Python2 are released. >> > > So this implies, just build it for Python 2 and deploy it, and if it > works well enough, leave it there until I figure out what rewrites are > necessary. Certainly possible, but I'm already tired of putting "u" in > front of my string constants Which you don't need to do. > and of converting from QString back to > unicode... ...and avoiding that will be a benefit of moving to PyQt for Py3. It's up to you. Obviously you can take sensible steps when designing your app to minimise the changes - keep your GUI code separate from your models and business logic, add some "compatibility wrapper" stuff that makes sense in the context of your own app. What I will try and do - probably via the wiki - is to document what the incompatibilities will be (though it will be a moving target) so that people can try and write for both Py2 and Py3 if that's appropriate for their app. Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
