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On Fri, 8 Oct 2021 at 16:29, Jelle Zijlstra <jelle.zijlstra@gmail.com> wrote:
That's one of the differences between the proposals discussed here. The basic proposal Pradeep pointed out would not support named arguments, the more complete syntax favored by Guido (and also by me; 2(a) in Pradeep's email) would support it.
Pradeep has done some empirical analysis that shows that in practice it is not very common to use such types, though.
I believe resolvelib (used by pip) makes a point of always calling callbacks with named arguments, to ensure compatibility. I thought PEP 517 hooks also required callers to use keywords, but when I checked the PEP, apparently not. I think with hindsight that we should have, though. But yes, I can imagine that simpler callbacks (like key= in sort) would be more common, and would be fine with positional arguments. Paul