[Python-Dev] Re: Re: accumulator display syntax

Terry Reedy tjreedy at udel.edu
Mon Oct 20 18:47:49 EDT 2003




"Guido van Rossum" <guido at python.org> wrote in message
news:200310201815.h9KIFM821583 at 12-236-54-216.client.attbi.com...
> > Most of us seem to agree that having list comprehensions
> > available as a replacement for map() and filter() is a good
> > thing. But what about reduce()? Are there equally strong
> > reasons for wanting an alternative to that, too? If not,
> > why not?
>
> If anything, the desire there is *more* pressing.  Except for
> operator.add, expressions involving reduce() are notoriously hard to
> understand (except to experienced APL or Scheme hackers :-).
>
> Things like sum, max, average etc. are expressed very elegantly with
> iterator comprehensions.
>
> I think the question is more one of frequency of use.  List comps
have
> nothing over e.g.
>
>   result = []
>   for x in S:
>       result.append(x**2)
>
> except compactness of exprssion.  How frequent is
>
>   result = 0.0
>   for x in S:
>       result += x**2
>
> ???
>
> (I've already said my -1 about your 'sum of ...' proposal.)
>
> --Guido van Rossum (home page: http://www.python.org/~guido/)
>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> http://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe:
http://mail.python.org/mailman/options/python-dev/python-python-dev%40m.gmane.org
>






More information about the Python-Dev mailing list