FWIW, I like ?? It is short and distinctive. There is prior art in this spelling in c#. It requires no new keyword, nor does it give new meaning to an existing one.
I understand why ?[ needs to be spelled using only a single ?, but I am afraid it will be used infrequently, and people will accidentally write a??[x] which is legal but different. I found the example code in the PEP using ?. and ?[ hard to read. ?? and ??= are compelling, though. One more question: what does this do? del x x ??= 42 Stephan Op do 19 jul. 2018 15:00 schreef Judah Levy <judah.j.l...@gmail.com>: > On Thu, Jul 19, 2018 at 8:47 AM Rhodri James <rho...@kynesim.co.uk> wrote: > >> On 19/07/18 09:33, Antoine Pitrou wrote: >> > There is a use case I sympathize with: the argument-is-None case. For >> > that I would suggest a simpler form: "A else B" which would evaluate >> > to A if A is not None, otherwise to B (parentheses may be mandatory). >> > >> > So e.g. one of the examples would read: >> > >> > def insort_right(a, x, lo=0, hi=None): >> > # ... >> > hi = hi else len(a) >> > # ... >> >> Much as I would like a keyword, "else" is the wrong one. It implies we >> are dealing with truthiness, which we aren't, and lays a subtle semantic >> trap as a consequence. >> >> If anyone can think of a good word for "if it isn't None, otherwise", >> I'd be all for it :-) >> >> -- >> Rhodri James *-* Kynesim Ltd >> _______________________________________________ >> Python-ideas mailing list >> Python-ideas@python.org >> https://mail.python.org/mailman/listinfo/python-ideas >> Code of Conduct: http://python.org/psf/codeofconduct/ >> > > I think that it may look better with the order switched and the word > unless, as in > > def insort_right(a, x, lo=0 hi=None): > # ... > hi = len(a) unless hi > # ... > > Unfortunately, this does maybe feel more like checking for truthiness than > non-Null value > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ >
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