> Scientific applications want something like > > {'a': 10, 'b': "foo", 'c': {'this': b'123'}} > > as an ordered initializer for unboxed or typed (or both) data. In general, > if dicts are ordered, they can be used for example as initializers for > (nested) C structs.
I can understand why you'd want an ordered container, I just don't see why it must be a dict. Why can't it be: OrderedDict(a=10, b='foo', c=OrderedDict(this=b'123')) Is it just that you don't want to type OrderedDict that many times? If it's so important to provide ordered dictionary literals, I would think it's a no-brainer to give them their own literal syntax (rather than re-defining dicts to have guaranteed order). e.g.: o{'a': 10, 'b': 'foo', 'c': o{'this': b'123'} Then there is no backwards incompatibility problem and users can express whether order does or does not matter to them when initializing a container. On 11/05/2017 01:39 PM, Stefan Krah wrote: > On Sun, Nov 05, 2017 at 01:14:54PM -0500, Paul G wrote: >> I'm not entirely sure I understand the full set of reasoning for this - I >> couldn't really tell what the problem with OrderedDict is from the link >> Stefan provided. It seems to me like a kind of huge change for the language >> to move from arbitrary-ordered to guaranteed-ordered dict. The problem I see >> is that this introduces a huge backwards compatibility burden on all >> implementations of Python. > > > > >> 2. Someone invents a new arbitrary-ordered container that would improve on >> the memory and/or CPU performance of the current dict implementation > > I would think this is very unlikely, given that the previous dict > implementation > has always been very fast. The new one is very fast, too. > > > > Stefan Krah > > > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/paul%40ganssle.io >
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