Pre-PEP: Dictionary accumulator methods

[Raymond Hettinger]

[Jeff Epler]
> Maybe something for sets like 'appendlist' ('unionset'?)

While this could work and potentially be useful, I think it is better to keep
the proposal focused on the two common use cases.  Adding a third would reduce
the chance of acceptance.

Also, in all of my code base, I've not run across a single opportunity to use
something like unionset().  This is surprising because I'm the set() author and
frequently use set based algorithms.    Your example was a good one and I can
also image a graph represented as a dictionary of sets.  Still, I don't mind
writing out the plain Python for this one if it only comes up once in a blue
moon.


Raymond