On Thu, Sep 10, 2009 at 4:51 PM, David Perlman <dperl...@wisc.edu> wrote: > Well, here's what I am really doing: > > class oneStim(str): > def __init__(self, time, mods=[], dur=None, format='%1.2f'): > self.time=time > self.mods=mods > self.dur=dur > self.format=format
This is a bit odd because you don't call str.__init__() so you never initialize the "str" part of a oneStim. Actually when you subclass immutable, built-in classes you have to override __new__() rather than __init__(). Here is an example: http://mail.python.org/pipermail/python-list/2004-June/265368.html > The purpose of this is to make an object that holds a collection of numbers > and represents them as a specifically formatted string. I want to be able > to do something like: > >>>> z=oneStim(22.5678) >>>> z.dur=10 >>>> z > 22.57:10.00 >>>> len(z) > 11 >>>> z.rjust(20) > ' 22.5678' > > Note that that doesn't work either. You are expecting that str.rjust() accesses the string using __repr__() but it doesn't, it directly accesses the internal data. > It works fine like this, though: >>>> z > 22.57:10.00 >>>> str(z).rjust(20) > ' 22.57:10.00' > > I can work with that just fine, but I am curious to understand what's going > on under the hood that makes it fail when subclassed from str... I would skip the cleverness of trying to subclass string. You can use str(z).rjust(20) as above, or use string formatting: '%20s' % z Kent _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
