localizing a sort

[Alex Martelli]

Ricardo Aráoz <ricaraoz at gmail.com> wrote:
> Peter Otten wrote:
   ...
> >>>>> print ''.join(sorted(a, cmp=lambda x,y: locale.strcoll(x,y)))
> >> aeiouàáäèéëìíïòóöùúü
> > 
> > The lambda is superfluous. Just write cmp=locale.strcoll instead.
> 
> No it is not :
> >>> print ''.join(sorted(a, cmp=locale.strcoll(x,y)))
> Traceback (most recent call last):
>   File "<input>", line 1, in <module>
> TypeError: strcoll expected 2 arguments, got 0
> 
> You need the lambda to assign both arguments.

No, your mistake is that you're CALLING locale.strcoll, while as Peter
suggested you should just PASS it as the cmp argument.  I.e.,

    ''.join(sorted('ciao', cmp=locale.strcoll))

Using key=locale.strxfrm should be faster (at least when you're sorting
long-enough lists of strings), which is why strxfrm (and key=...:-)
exist in the first place, but cmp=locale.strcoll, while usually slower,
is entirely correct.  That lambda _IS_ superfluous, as Peter said.


Alex