On Wed, Apr 30, 2008 at 4:14 PM, Greg Ewing <[EMAIL PROTECTED]> wrote: > Guido van Rossum wrote: > > > > > On Wed, Apr 30, 2008 at 3:49 PM, Greg Ewing <[EMAIL PROTECTED]> > wrote: > > > > > > > > > So that code will silently behave as though the rest of > > > the sequence wasn't there some of the time? > > > > > > > Only if it uses LBYL. > > > > I don't understand that. Iteration isn't the only thing > one does with sequences. If you have a reason to call > len() in the first place, I don't see how having it > sometimes return inaccurate results can be helpful.
I've come across situations where len() raising an exception was more inconvenient than returning a truncated value (e.g. when printing). > > > Can you elaborate on the rationale for this? > > > > > > > > > Ask the designers of the Java collections package. > > > > Do you mean that they have a rationale which you agree > with and think applies to Python as well, or do you > mean that you're doing it just because Java does it > and they must have a good reason? > > If the former, can you refer me to a document which > espouses it? You'll have to do some research, but I believe the circumstances are similar -- they have a size() method that is defined to return an unboxed int, so they are limited by that. I found the spec here: http://java.sun.com/j2se/1.4.2/docs/api/java/util/Collection.html#size() But I didn't find a rationale. I'm sure it was PBP though. -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
