Duncan Booth wrote: > Raymond Hettinger wrote: > > > The rationale is to replace the awkward and slow existing idioms for > > dictionary based accumulation: > > > > d[key] = d.get(key, 0) + qty > > d.setdefault(key, []).extend(values) > > > > How about the alternative approach of allowing the user to override the > action to be taken when accessing a non-existent key? > > d.defaultValue(0) > > and the accumulation becomes: > > d[key] += 1 > > and: > > d.defaultValue(function=list) > > would allow a safe: > > d[key].extend(values)
+0 The best suggestion up to now. But i find this premature because it addresses only a special aspect of typing issues which should be disussed together with Guidos type guard proposals in a broader context. Besides this the suggestion though feeling pythonic is still uneven. Why do You set d.defaultValue(0) d.defaultValue(function=list) but not d.defaultValue(0) d.defaultValue([]) ? And why not dict(type=int), dict(type=list) instead where default values are instantiated during object creation? A consistent pythonic handling of all types should be envisioned not some ad hoc solutions that go deprecated two Python releases later. Regards Kay -- http://mail.python.org/mailman/listinfo/python-list
