[Python-ideas] Fwd: unpacking generalisations for list comprehension

[Paul Moore]

On 12 October 2016 at 20:22, David Mertz <mertz at gnosis.cx> wrote:
> I've followed this discussion some, and every example given so far
> completely mystifies me and I have no intuition about what they should mean.

Same here.

On 12 October 2016 at 20:38, אלעזר <elazarg at gmail.com> wrote:
> What is the intuition behind [1, *x, 5]? The starred expression is replaced
> with a comma-separated sequence of its elements.
>
> The trailing comma Nick referred to is there, with the rule that [1,, 5] is
> the same as [1, 5].
>
> All the examples follow this intuition, IIUC.

But intuition is precisely that - it's not based on rules, but on
people's instinctive understanding. When evaluating whether something
is intuitive, the *only* thing that matters is what people tell you
they do or don't understand by a given construct. And in this case,
people have been expressing differing interpretations, and confusion.
That says "not intuitive" loud and clear to me.

And yes, I find [1, *x, 5] intuitive. And I can't tell you why I find
it OK, but I find {**x for x in d.items()} non-intuitive. But just
because I can't explain it doesn't mean it's not true, or you can
"change my mind" about how I feel.

Paul