How about this, Brendan? _, x1, x2 = (D := b**2 - 4*a*c), (-b + sqrt(D))/2, (-b - sqrt(D))/2
I'm not sure I love this, but I don't hate it. On Wed, Apr 11, 2018, 12:50 PM Brendan Barnwell <brenb...@brenbarn.net> wrote: > On 2018-04-11 05:23, Clint Hepner wrote: > > I find the assignments make it difficult to pick out what the final > expression looks like. > > I strongly agree with this, and for me I think this is enough to > push > me to -1 on the whole proposal. For me the classic example case is > still the quadratic formula type of thing: > > x1, x2 = (-b + sqrt(b**2 - 4*a*c))/2, (-b - sqrt(b**2 - 4*a*c))/2 > > It just doesn't seem worth it to me to create an expression-level > assignment unless it can make things like this not just less verbose but > at the same time more readable. I don't consider this more readable: > > x1, x2 = (-b + sqrt(D := b**2 - 4*a*c)))/2, (-b - sqrt(D))/2 > > . . . because having to put the assignment inline creates a visual > asymmetry, when for me the entire goal of an expression-level statement > is to make the symmetry between such things MORE obvious. I want to be > able to write: > > x1, x2 = (-b + sqrt(D)))/2, (-b - sqrt(D))/2 ... > > . . . where "..." stands for "the part of the expression where I define > the variables I'm re-using in multiple places in the expression". > > The new proposal does at least have the advantage that it would > help > with things like this: > > while x := some_function_call(): > # do stuff > > So maybe I'm -0.5 rather than -1. But it's not just that this > proposal > "could be used to create ugly code". It's that using it for > expression-internal assignments WILL create ugly code, and there's no > way to avoid it. I just don't see how this proposal provides any way to > make things like the quadratic formula example above MORE readable. > > -- > Brendan Barnwell > "Do not follow where the path may lead. Go, instead, where there is no > path, and leave a trail." > --author unknown > _______________________________________________ > 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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