On Tue, Jul 21, 2020 at 05:48:35PM -0700, Christopher Barker wrote:
> for something in some_iterable:
> some_stuff_with_maybe_a_break
> else: # if not break:
> something_more
>
> and no changes needed to Python!
>
> I may actually start doing that myself ...
I always do that, not because I need it now, but because the next person
who reads my code in six months might need it.
That person might even be me.
> As for the "loop didn't run at all" case: Does anyone find a need for that?
> Personally, I've found that everytime I do some kind of check for an empty
> iterable before a loop, it was totally unnecessary.
If we had it, I would use it. It is generally possible to work around
the lack, e.g. with an explicit test of a sequence (but that doesn't
work with iterators), but I find that sometimes it isn't *obvious* that
the empty loop case is handled correctly:
for x in iterable:
do stuff
continue processing
If iterable is empty, is the code still correct? Sometimes that's
obvious, but when it *isn't* obvious I wish there was a way to run this:
for x in iterable:
do stuff
if loop was empty:
whatever is needed to make it obviously correct
such as an assert, or early return
I'd rather have an extra couple of lines of code and obviously correct
code than save a few lines and have to think hard about whether the code
is correct :-)
More rarely I do need to treat the empty case specially. If the iterator
is a sequence I can test the length up front, but this doesn't work with
iterables.
It's not *hard* to work around this, it's just inelegant.
--
Steven
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