Steven D'Aprano wrote:
On Mon, 14 Mar 2011 12:10:27 +0100, Jean-Michel Pichavant wrote:
Steven D'Aprano wrote:
The removal of cmp from the sort method of lists is probably the most
disliked change in Python 3. On the python-dev mailing list at the
moment, Guido is considering whether or not it was a mistake.
If anyone has any use-cases for sorting with a comparison function that
either can't be written using a key function, or that perform really
badly when done so, this would be a good time to speak up.
You seem concerned by this removal, do you have any use-case ?
You seem concerned by my concern. Why do you think I am concerned?
(1) I'm not concerned, but many people are. If you search the archives of
this newsgroup (mailing list), you'll see that I have defended the
removal of cmp from sort, e.g. this post:
http://www.mail-archive.com/python-list%40python.org/msg261728.html
(2) If I had a good use-case for keeping cmp, I wouldn't need to ask
others if they had a good use-case.
As it is, Guido himself has mentioned one such good use for a comparison
function when sorting. Use of a key function trades off memory for time,
while sorting with a comparison function makes the opposite trade off,
using more time for the sake of saving memory.
Just to know if currently the use-case count is zero. Nothing evil
hidden behind my question :p
JM
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