nn <prueba...@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. -- http://mail.python.org/mailman/listinfo/python-list
