On Tue, Aug 28, 2018 at 6:05 PM, Stephen J. Turnbull
<turnbull.stephen...@u.tsukuba.ac.jp> wrote:
> In the case in point, the destructuring assignments
>
> a, b = b, a
> w, x, y, z = z, w, y, x
>
> can be interpreted as "swapping" or "permuting", and AIUI that's why
> they were included. They express the intent better than
>
> tmp = a
> a = b
> b = tmp
> del tmp
>
> and I don't want to even think about how to do the 4-variable version
> without 4 temporary variables. By comparison,
>
> x, y += a, b
>
> is neither more expressive, nor easier to read, nor significantly
> harder to type, than
>
> x += a
> y += b
>
> as far as I can see.
When you have completely different variables, sure. But what if - like
in the swap example - they're the same variables?
def frobnicate():
a, b, c = 1, 10, 100
while True:
a, b, c += b, c, a
yield a
On the first iteration, this would be:
a += 10
b += 100
c += 1
I don't have an actual use-case, but to be fair, I also have very few
use-cases for swapping/permuting.
-0 on adding it, but it's not an illogical feature.
ChrisA
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