On May 9, 2020, at 02:12, Ram Rachum <[email protected]> wrote:
>
>
> Here's an idea I've had. How about instead of this:
>
> itertools.islice(iterable, 7, 20)
>
> We'll just have:
>
> itertools.islice(iterable)[7:20]
I’ve actually built this.[1] From my experience, it feels clever at first, but
it can get confusing.
The problem is that if you slice twice, or slice after nexting, you can’t get a
feel for what the remaining values should be unless you work it through. Of
course the exactly same thing is true with using islice twice today, but you
don’t _expect_ that to be comprehensible in terms of slicing the original
iterable twice, while with slice notation, you do. Or at least I do; maybe
that’s just me.
And meanwhile, even though the simple uses aren’t confusing, I’ve never had any
code where it made things nicer enough that it seemed worth reaching into the
toolbox. But again, maybe that’s just me.
If you want to play with this and can’t implement it yourself easily, I could
dig up my implementation. But it’s pretty easy (especially if you don’t try to
optimize and just have __getitem__ return a new islice around self).
—-
[1] Actually, I built an incomplete viewtools (a replacement for itertools plus
zip, map, etc. that gives you views that are reusable iterables and forward as
much input behavior as possible—so map(lambda i: i*2, range(10)) is a sequence,
while filter(lambda i: i%2, range(10)) is not a sequence but it is reversible,
and so on) and then extracted and simplified the vslice because I thought it
might be useful without the views stuff. (I also extracted and simplified it in
a different way, as view slices that only work on sequences, and that actually
did turn out to be occasionally useful.)
_______________________________________________
Python-ideas mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/[email protected]/message/CQ43LF5UICMYNNB43JJM2CXOILUOCSPC/
Code of Conduct: http://python.org/psf/codeofconduct/
