Guido rethinking removal of cmp from sort method

[Antoon Pardon]

On Wed, Mar 23, 2011 at 02:59:09PM +0100, Stefan Behnel wrote:
> Antoon Pardon, 23.03.2011 14:53:
> >On Sun, Mar 13, 2011 at 12:59:55PM +0000, 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.
> >
> >How about a list of tuples where you want them sorted first item in ascending
> >order en second item in descending order.
> 
> You can use a stable sort in two steps for that.

Which isn't helpfull if where you decide how they have to be sorted is
not the place where they are actually sorted.

I have a class that is a priority queue. Elements are added at random but
are removed highest priority first. The priority queue can have a key or
a cmp function for deciding which item is the highest priority. It
can also take a list as an initializor, which will then be sorted.

So this list is sorted within the class but how it is sorted is decided
outside the class. So I can't do the sort in multiple steps.

-- 
Antoon Pardon