On 7/25/2013 12:21 PM, Ethan Furman wrote:
On 07/25/2013 09:11 AM, Prasad, Ramit wrote:
Hmm, that is a change that makes some sense to me. Does the view
get updated when dictionary changes or is a new view needed? I
assume the latter.
Nope, the former. That is a big advantage that the views have over
concrete lists: they show the /current/ state, and so are always
up-do-date.
I think 'view' is generally used in CS to mean a live view, as opposed
to a snapshot. Memoryviews in 3.x are also live views. Dictionary views
are read-only. I believe memoryviews can be read-write if allowed by the
object being viewed.
Python slices are snapshots. It has been proposed that they should be
views to avoid copying memory, but that has been rejected since views
necessarily keep the underlying object alive. Instead, applications can
define the views they need. (They might, for instance, allow multiple
slices in a view, as tk Text widgets do.)
--
Terry Jan Reedy
--
http://mail.python.org/mailman/listinfo/python-list
