On 3/19/2012 6:04 PM, Guido van Rossum wrote:
On Mon, Mar 19, 2012 at 2:58 PM, Peter Moody<pmo...@google.com> wrote:
On Mon, Mar 19, 2012 at 12:55 PM, Guido van Rossum<gu...@python.org> wrote:
On Mon, Mar 19, 2012 at 12:37 PM, Ethan Furman<et...@stoneleaf.us> wrote:
Nick Coghlan wrote:
Collapsing the address list has to build the result list anyway to
actually handle the deduplication part of its job, so returning a
concrete list makes sense in that case.
Having only one function return a list instead of an iterator seems
questionable.
Depending on the code it could either keep track of what it has returned so
far in a set and avoid duplication that way; or, just return an
`iter(listobject)` instead of `listobject`.
I know I'm lacking context, but is the list ever expected to be huge?
If not, what's wrong with always returning a list?
It's possible to return massive lists, (eg, returning the 4+ billion
/128 subnets in /96 or something even larger, but I don't think that's
very common). I've generally tried to avoid confusion by having 'iter'
in the iterating methods, but if more of the methods return iterators,
maybe I need to rethink that?
I personally like having 'iter' in the name (e.g. iterkeys() -- note
that we dropped this in Py3k because it's no longer an iterator, it's
a dict view now. But I don't want to promote that style for ipaddr.py.
I am not sure which way you are pointing, but the general default in 3.x
is to return iterators: range, zip, enumerate, map, filter, reversed,
open (file objects), as well at the dict methods. I am quite happy to be
rid of the 'iter' prefix on the latter. This is aside from itertools.
The main exceptions I can think of are str.split and sorted. For sorted,
a list *must* be constructed anyway, so might as well return it. This
apparently matches the case under consideration. If name differentiation
is wanted, call it xxxlist.
--
Terry Jan Reedy
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