On Tue, May 31, 2016 at 1:22 PM, Paul Moore <p.f.moore@gmail.com> wrote:
but I'm not at all sure that needing 2 new keywords ("export" and "key") and a reuse of an existing one ("from") is going to fly - it's too wordy, feels like SQL or COBOL to me. Maybe if someone comes up with a one-word option for "export key from" then it would be viable...
As two words: fromdict <expression evaluating to dict> import <valid identifier>[ as <valid identifier>][, <valid identifier>[, ...]] IMO: - The desired feature really is more like import than unpacking. It's only different in that one is a lookup to d.__getitem__ while the other is a file lookup, then a load, then (I believe) a lookup to vars(module).__getitem__. - Don't repeat the key. - The names being introduced should be syntactic tokens, [so that || because] the compiler knows to make cells in locals() for those names. - The mapping should be named first. (TBF, I also think that, in comprehensions, the item should be named before the expression using it, so maybe my senses are wrong.) - The syntax should make it obvious that a dict-like object is expected, even to those who haven't seen it before. Leading `extract` and `export` don't satisfy that. (`extract key` makes me itch when I see more than one key follow, and it isn't clear without reading further that "key" isn't what's being extracted.) - As long as it is clear from the start of the line whether it is a module or a dict being imported, it's okay to use `import`. It's too bad "fromdict" is used in the wild (https://pythonhosted.org/dictalchemy/#dictalchemy.utils.fromdict), and "frommapping" is too long (in letters, syllables, and constituent parts: "from", "map", and "-ing"). `fromdict d import *`: People might expect this, for symmetry with `from ... import *`. In CPy, there's no sense of dynamically-created local names (since locals are looked up in the compiler), and you couldn't use them anyway. (We don't talk about `eval` and `exec`.) In global scope, `import *` makes more sense, but I think you can just say, "If you need something like that, you should've created a module instead." Possible (gross) extensions: fromdict d import 'literalstring' as name2, (evaluatedname) as name2