
On Thu, Mar 1, 2012 at 12:35 PM, André Malo <nd@perlig.de> wrote:
* Guido van Rossum wrote:
On Thu, Mar 1, 2012 at 9:44 AM, Victor Stinner <victor.stinner@gmail.com> wrote:
frozendict would help pysandbox but also any security Python module, not security, but also (many) other use cases ;-)
Well, let's focus on the other use cases, because to me the sandbox use case is too controversial (never mind how confident you are :-).
I like thinking through the cache use case a bit more, since this is a common pattern. But I think it would be sufficient there to prevent accidental modification, so it should be sufficient to have a dict subclass that overrides the various mutating methods: __setitem__, __delitem__, pop(), popitem(), clear(), setdefault(), update().
For the caching part, simply making the dictproxy type public would already help a lot.
Heh, that's a great idea. Can you file a bug for that?
What other use cases are there?
dicts as keys or as set members. I do run into this from time to time and always get tuple(sorted(items()) or something like that.
I know I've done that once or twice in my life too, but it's a pretty rare use case and as you say the solution is simple enough. An alternative is frozenset(d.items()) -- someone should compare the timing of these for large dicts. -- --Guido van Rossum (python.org/~guido)