[Python-Dev] Set methods for mapping views (original) (raw)

Steven D'Aprano steve at pearwood.info
Mon Oct 26 23:59:43 CET 2009

On Tue, 27 Oct 2009 08:54:52 am Nick Coghlan wrote:

Raymond Hettinger wrote: > [GvR] > >> I still wish we could go back in time and unify sets and dicts, if >> only to find out how that experiment would turn out. > > I'm curious about the outcome of another experiment along those > lines. Is anyone seeing uptake for the set methods on mapping views > in Py3.x? > > I haven't seen any code using it, nor any bug reports or > documentation requests, nor any code in the ASPN cookbook, nor > mention of it on the newsgroup or python-help. > > Has anyone here seen any hints about how this is faring in the > wild?

If anyone is looking for further explanation as to why Guido's moratorium on core language changes is a good idea, allowing a chance for answers to questions like Raymond's above a chance to evolve naturally is what I see as the most important rationale.

I don't understand that rationale. Let's take a concrete example. The new yield from syntax was accepted but now will be delayed by the moratorium. How would the addition of yield from delay or prevent people using set methods on mapping views?

If a proposed feature directly competes with a feature in 3.x, then it might delay usage of the 3.x feature -- but if that were the case, the proposal would almost certainly be rejected on the basis that 3.x already has a feature to do that very thing.

-- Steven D'Aprano

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