On Tue, Jul 25, 2017 at 7:49 PM, MRAB <pyt...@mrabarnett.plus.com> wrote:
> On 2017-07-25 02:57, Nick Coghlan wrote: > >> On 25 July 2017 at 02:46, Michel Desmoulin <desmoulinmic...@gmail.com> >> wrote: >> >>> Le 24/07/2017 à 16:12, Nick Coghlan a écrit : >>> >>>> On 22 July 2017 at 01:18, Guido van Rossum <gu...@python.org> wrote: >>>> >>>>> Honestly I would like to declare the bare (x=1, y=0) proposal dead. >>>>> Let's >>>>> encourage the use of objects rather than tuples (named or otherwise) >>>>> for >>>>> most data exchanges. I know of a large codebase that uses dicts >>>>> instead of >>>>> objects, and it's a mess. I expect the bare ntuple to encourage the >>>>> same >>>>> chaos. >>>>> >>>> >>> This is the people working on big code base talking. >>> >> >> Dedicated syntax: >> >> (x=1, y=0) >> >> New builtin: >> >> ntuple(x=1, y=0) >> >> So the only thing being ruled out is the dedicated syntax option, >> since it doesn't let us do anything that a new builtin can't do, it's >> harder to find help on (as compared to "help(ntuple)" or searching >> online for "python ntuple"), and it can't be readily backported to >> Python 3.6 as part of a third party library (you can't easily backport >> it any further than that regardless, since you'd be missing the >> order-preservation guarantee for the keyword arguments passed to the >> builtin). >> >> [snip] > > I think it's a little like function arguments. > > Arguments can be all positional, but you have to decide in what order they > are listed. Named arguments are clearer than positional arguments when > calling functions. > > So an ntuple would be like a tuple, but with names (attributes) instead of > positions. > > I don't see how they could be compatible with tuples because the positions > aren't fixed. You would need a NamedTuple where the type specifies the > order. > > I think... > > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ > Most likely ntuple() will require keyword args only, whereas for collections.namedtuple they are mandatory only during declaration. The order is the same as kwargs, so: >>> nt = ntuple(x=1, y=2) >>> nt[0] 1 >>> nt[1] 2 What's less clear is how isinstance() should behave. Perhaps: >>> t = (1, 2) >>> nt = ntuple(x=1, y=2) >>> isinstance(nt, tuple) True >>> isinstance(t, ntuple) False -- Giampaolo - http://grodola.blogspot.com
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