How to stop iteration with __iter__() ?

[John Machin]

On Aug 20, 7:56 pm, MRAB <goo... at mrabarnett.plus.com> wrote:
> On Aug 20, 12:11 am, John Machin <sjmac... at lexicon.net> wrote:
>
> > or, perhaps, for completeness/paranoia/whatever:
>
> > it = iter(iterable)
> > try:
> >    headings = it.next() # < 2.5
> > except StopIteration:
> >    # code to handle empty <iterable>
> > for item etc etc
>
> I think it needs to be:
>
> it = iter(iterable)
> try:
>     headings = it.next() # < 2.5
> except StopIteration:
>     # code to handle empty <iterable>
> else:
>     for item etc etc
>
> because you don't want to iterate over the remainder if it has already
> stopped yielding! :-)

If it has stopped yielding, the remainder is nothing/null/empty, isn't
it?
In any case "code to handle empty <iterable>" is likely to end with a
raise or return statement.

Cheers,
John