Is there a better way to do this snippet?

[nn]

On Apr 3, 12:26 pm, Alain Ketterlin <al... at dpt-info.u-strasbg.fr>
wrote:
> nn <prueba... at latinmail.com> writes:
> >> > for item in tag23gr:
> >> > ...        value, key = tuple(item)
> >> > ...        if(g23tag.get(key)):
> >> > ...                g23tag[key].append(value)
> >> > ...        else:
> >> > ...                g23tag[key] = [value]
>
> >> for item in tag23gr:
> >>     g23tag.setdefault(item[0],[]).append(item[1])
> > Or alternatively:
>
> > from collections import defaultdict
> > g23tag = defaultdict(list)
> > for item in tag23gr:
> > ....g23tag[item[0]].append(item[1])
>
> Very handy in that case, but in general I dislike the idea of silently
> inserting a default value when the access is a read, e.g., in
> x=g23tag[wrung]. Explicit is better than implicit, as they say. YMMV.
>
> -- Alain.

Valid point. Preferred choice depends on the access patterns to the
dict (e.g. one write and multiple reads, multiple writes and one loop
over items, etc.)