On 10 Mar 2018, Paul Moore wrote (in article<mailman.8.1520680557.1867.python-l...@python.org>):
> On 10 March 2018 at 02:18, MRAB<pyt...@mrabarnett.plus.com> wrote: > > On 2018-03-10 01:13, Steven D'Aprano wrote: > > > > > > I am trying to enumerate all the three-tuples (x, y, z) where each of x, > > > y, z can range from 1 to ∞ (infinity). > > > > > > This is clearly unhelpful: > > > > > > for x in itertools.count(1): > > > for y in itertools.count(1): > > > for z in itertools.count(1): > > > print(x, y, z) > > > > > > as it never advances beyond x=1, y=1 since the innermost loop never > > > finishes. > > > > > > Georg Cantor to the rescue! (Well, almost...) > [...] > > > Can anyone help me out here? > > Think about the totals of each triple. You'll get totals of 3, then totals > > of 4, etc. > > > > This might help, although the order they come out might not be what you > > want: > > > > def triples(): > > for total in itertools.count(1): > > for i in range(1, total): > > for j in range(1, total - i): > > yield i, j, total - (i + j) > > Mathematically, that's the usual generalisation of Cantor's diagonal argument. > > Paul Would a multi-dimensional Hilbert curve do the job? See the Wikipedia article for starters -- To de-mung my e-mail address:- fsnospam$elliott$$ PGP Fingerprint: 1A96 3CF7 637F 896B C810 E199 7E5C A9E4 8E59 E248 -- https://mail.python.org/mailman/listinfo/python-list
