> Care to repeat those arguments?


*Minimal use of characters*

The primary benefit for me would be the minimal use of characters, which within list comprehensions I think is not an insignificant benefit:
    stuff = [[(f(x) as y), x/y] for x in range(5)]      # seems quite syntactically busy
    stuff = [[y := f(x), x/y] for x in range(5)]        # better
    stuff = [[y! f(x), x/y] for x in range(5)]          # two fewer characters (if you include the space after the identifier)
*Thoughts on odd usage of "!"*
In the English language, `!` signifies an exclamation, and I am imagining a similar usage to that of introducing something by its name in an energetic way. For example a boxer walking in to the ring:
"Muhammed_Ali! <in walks Muhammed Ali>", "x! get_x()"
I get that `!` is associated with "not", and factorial, but I couldn't think of another character already used that would work in this usage. I also think `name! expression` would be hard to interpret as a comparison or factorial. I suppose the trade off here is efficiency vs. idiosyncrasy. I very much appreciate this is all very tentative, but I wanted to explain why this syntax does not sit terribly with me.

On 7 April 2018 at 00:49, Steven D'Aprano <steve@pearwood.info> wrote:
On Fri, Apr 06, 2018 at 03:27:45PM +0000, Cammil Taank wrote:
> I'm not sure if my suggestion for 572 has been considered:
> ``name! expression``
> I'm curious what the pros and cons of this form would be (?).

I can't see any pros for it. In what way is ! associated with assignment
or binding? It might as well be a arbitrary symbol.

(Yes, I know that ultimately *everything* is an arbitrary symbol, but
some of them have very strong associations built on years or decades or
centuries of usage.)

As Peter says, ! is associated with negation, as in !=, and to those of
us with a maths background, name! simply *screams* "FACTORIAL" at the
top of its voice.

> My arguments for were in a previous message but there do not seem to be any
> responses to it.

Care to repeat those arguments?

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