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

[Steven D'Aprano]

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)


which needlessly duplicates almost the entire string just to skip the 
first char. The same applies to lists or other sequences.

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?



-- 
Steve