[Python-ideas] Why don't CPython strings implement slicing using a view?

[Neil Girdhar]

The point is to have a Pythonic way of saying that.  Using islice or
iterating over a range and indexing is ugly.  It would be cleaner to
implement a string class that implements fast slicing than those unpythonic
pieces of code.

Best,

Neil

On Thu, May 7, 2015 at 2:26 PM, Terry Reedy <tjreedy at udel.edu> wrote:

> On 5/7/2015 11:46 AM, Steven D'Aprano wrote:
>
>> On Wed, May 06, 2015 at 07:05:15PM -0700, Neil Girdhar wrote:
>>
>>> Since strings are constant, wouldn't it be much faster to implement
>>> string
>>> slices as a view of other strings?
>>>
>>
>> String or list views would be *very* useful in situations like this:
>>
>> # Create a massive string
>> s = "some string"*1000000
>> for c in s[1:]:
>>      process(c)
>>
>
> Easily done without slicing, as discussed on python-list multiple times.
>
> it = iter(s)
> next(it)
> for c in it: process(c)
>
> for s[5555: 399999], use explicit indexes
>
> for i in range(5555, 400000): process s[i]
>
> or use islice.
>
> The use case for sequence views is when one needs to keep around both the
> base sequence and the slices (views).
>
> --
> Terry Jan Reedy
>
>
> _______________________________________________
> Python-ideas mailing list
> Python-ideas at python.org
> https://mail.python.org/mailman/listinfo/python-ideas
> Code of Conduct: http://python.org/psf/codeofconduct/
>
> --
>
> --- You received this message because you are subscribed to a topic in the
> Google Groups "python-ideas" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/python-ideas/II-4QRDb8Is/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> python-ideas+unsubscribe at googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20150507/d622d65b/attachment.html>