On Wed, Apr 25, 2012 at 3:26 AM, Phil Thompson <p...@riverbankcomputing.com> wrote: > On Tue, 24 Apr 2012 14:28:02 -0400, Deniz Turgut <dtur...@gmail.com> > wrote: >> Would it be logical to add a __nonzero__ method to QPyNullVariant >> which always returns False? >> >> I was going through a code of mine which broke with a new version of >> PyQt. I realized that it was because there is no __nonzero__ method in >> QPyNullVariant so bool(QPyNullVariant) is always True. >> >> Right now, if you use QVariant api 2, you can't check nicely (without >> typechecking) whether you get a nonzero value or Null/Falsy value. > > From a purist point of view I don't associate Null with False (or with > True either but the current behaviour reflects the Python default). > > From a portability point of view it's a change in the API. > > From a pragmatic point of view I need to be persuaded - I've not been > affected by the issue myself.
Actually, pragmatic part is not much of a big deal. Although it looks a bit ugly to me, I can live with code like: if value and not isinstance(value, QtCore.QPyNullVariant): do_something_with(value) Or I could deal with it much before, and eliminate a Null possibility. I guess my issue is closer to the purist view. I do agree that Null is neither True, nor False, but I'd expect it to behave like None. It is not False but rather Falsy. That's why, I spent some time figuring out why a test like 'if value:' was passing when a Null was returned. -- Deniz _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
