[Tutor] Chutes & Ladders

[Mark Lawrence]

On 23/12/2013 06:07, Keith Winston wrote:
> On Sun, Dec 22, 2013 at 3:04 PM, <tutor-request at python.org
> <mailto:tutor-request at python.org>> wrote:
>
>
>     games = [p1.gameset(gamecount) for _ in range(multicount)]
>
>
> So Peter gave me a list of suggesttions, all of which I've incorporated
> and gotten running, and it's been instructive.
>
> But in my haste I included the line above, cut & pasted from his
> suggestion, without understanding what the underscore is doing in there.
> I think I understand that at the prompt of the interpreter the
> underscore returns the last value returned... but I can't really figure
> out what it's doing here.
>
> Also: this statement worked fine:
>
> for tmulti in games:
>      print("{moves:9.2f} {chutes:12.2f} {ladders:13.2f}".format(
>              moves=mean(tgset[1] for tgset in tmulti),
>              chutes=mean(tgset[2] for tgset in tmulti),
>              ladders=mean(tgset[3] for tgset in tmulti)
>              ))
>
> Which is sort of awesome to me, but in my efforts to riff on it I've
> been stumped: if I want to further process the arrays/lists my list
> comprehensions are generating, I sort of can't, since they're gone: that
> is, if I wanted to use the entire len(tmulti) of them to determine grand
> total averages and variances, I can't. And if my array is large, I
> woudn't want to iterate over it over and over to do each of these steps,
> I think. Anyway, I'm just goofing on all this, for the learning value,
> but I'll appreciate any thoughts. Thanks.
>
> I'm also trying to speed up the program at this point: the way I've set
> it up now it builds a list of lists (of lists) of all the stats of all
> the games of all the gamesets of all the multisets. I've visually
> streamlined it some, without any effect on performance I can detect.
> Would using arrays, or tuples, or something else be likely to be faster?
> It's interesting that running it on my 8 y.o. Core 2 Duo and my 2 y.o.
> Core I5 result in virtually exactly the same speed. Weird. Obviously,
> it's just doing simple math, pretty much
>
> --
> Keith
>

Maybe this helps https://wiki.python.org/moin/PythonSpeed/PerformanceTips ?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence