[Python-ideas] discontinue iterable strings

[Steven D'Aprano]

On Sun, Aug 21, 2016 at 12:34:02AM +0000, Michael Selik wrote:

> So anything that wants to loop over a string character by character would
> need to construct a new object, like ``for c in list(s)``? That seems
> inefficient. I suppose you might advocate for a new type, some sort of
> stringview that would allow iteration over a string, but avoid allocating
> so much space as a list does, but that might bring us back to where we
> started.

If this was ten years ago, and we were talking about backwards 
incompatible changes for the soon-to-be-started Python 3000, I might be 
more responsive to changing strings to be an atomic type (like ints, 
floats, etc) with a .chars() view that iterates over the characters. Or 
something like what Go does (I think), namely to distinguish between 
Chars and Strings: indexing a string gives you a Char, and Chars are not 
indexable and not iterable.

But even then, the change probably would have required a PEP. 


> > The fixes overall will be a lot easier and obvious than introduction of
> > unicode as default string type in Python 3.0.
> 
> That's a bold claim. Have you considered what's at stake if that's not true?

Saying that these so-called "fixes" (we haven't established yet that 
Python's string behaviour is a bug that need fixing) will be easier and 
more obvious than the change to Unicode is not that bold a claim. Pretty 
much everything is easier and more obvious than changing to Unicode. :-)
(Possibly not bringing peace to the Middle East.)

I think that while the suggestion does bring some benefit, the benefit 
isn't enough to make up for the code churn and disruption it would 
cause. But I encourage the OP to go through the standard library, pick a 
couple of modules, and re-write them to see how they would look using 
this proposal.


-- 
Steve