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

Mark Lawrence breamoreboy at yahoo.co.uk
Sat May 9 10:51:18 CEST 2015 
On 09/05/2015 08:31, Andrew Barnert via Python-ideas wrote:
> On May 8, 2015, at 21:04, Nikolaus Rath <Nikolaus at rath.org> wrote:
>>
>>> On May 07 2015, Steven D'Aprano <steve-iDnA/YwAAsAk+I/owrrOrA at public.gmane.org> wrote:
>>> But a view would be harmful in this situation:
>>>
>>> s = "some string"*1000000
>>> t = s[1:2]  # a view maskerading as a new string
>>> del s
>>>
>>> Now we keep the entire string alive long after it is needed.
>>>
>>> How would you solve the first problem without introducing the second?
>>
>> Keep track of the reference count of the underlying string, and if it
>> goes down to one, turn the view into a copy and remove the sliced
>> original?
>
> Of course I could be wrong; we won't really know until someone actually builds at least an implementation and tests it.

Well they can, but I found a major problem with views is that you can't 
compare them and so can't sort them, thus rendering them useless for a 
lot of applications.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence
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