[Python-Dev] Single- vs. Multi-pass iterability

[Guido van Rossum]

> I'm having a hard time getting excited about this.  If you had made
> this argument before the iterator protocol was implemented, it may
> have been more or less intriguing.  But it was implemented and
> released some time ago, and I just haven't seen any evidence of such
> problems on c.l.py, the Help list, or the Tutor list (all of which I
> still pay significant attention to).

This is an important argument IMO that the theorists here seem to be
missing somewhat.  Releasing a feature and monitoring feedback is a
good way of user testing, something that has been ignored too often by
language designers.  Elegant or minimal abstractions have their place;
but in the end, users are more important.

Quoting Steven Pemberton's home page (http://www.cwi.nl/~steven/):

    ABC: Simple but Powerful Interactive Programming Language and
    Environment. : A Simple but Powerful Interactive Programming
    Language and Environment. We did requirements and task analysis,
    iterative design, and user testing. You'd almost think programming
    languages were an interface between people and computers. Now
    famous because Python was strongly influenced by it.

I still favor this approach to language design.

--Guido van Rossum (home page: http://www.python.org/~guido/)