[Python-Dev] decorate-sort-undecorate

Ian Bicking ianb at colorstudy.com
Wed Oct 15 15:48:04 EDT 2003

On Wednesday, October 15, 2003, at 12:35 PM, Barry Warsaw wrote:
> While we're hacking on [].sort(), how horrible would it be if we
> modified it to return self instead of None?  I don't mind the
> sort-in-place behavior, but it's just so inconvenient that it doesn't
> return anything useful.  I know it would be better if it returned a new
> list, but practicality beats purity. <wink>

When doing DSU sorting, the in-place sorting isn't really a performance 
win, is it?  You already have to allocate and populate an entire 
alternate list with the sort keys, though I suppose you could have 
those mini key structs point to the original list.

Anyway, while it's obviously in bad taste to propose .sort change its 
return value based on the presence of a key, wouldn't it be good if we 
had access to the new sorted list, instead of always clobbering the 
original list?  Otherwise people's sorted() functions will end up 
copying lists unnecessarily.

Okay, really I'm just hoping for [x for x in l sortby key(x)], if not 
now then someday -- if only there was a decent way of expressing that 
without a keyword... [...in l : key(x)] is the only thing I can think 
of that would be syntactically possible (without introducing a new 
keyword, new punctuation, or reusing a wholely inappropriate existing 
keyword).  Or ";" instead of ":", but neither is very good.


Ian Bicking | ianb at colorstudy.com | http://blog.ianbicking.org

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