Looking for feedback on weighted voting algorithm

[justin walters]

On Apr 14, 2016 9:41 AM, "Martin A. Brown" <martin at linux-ip.net> wrote:
>
>
> Greetings Justin,
>
> >    score = sum_of_votes/num_of_votes
>
> >votes = [(72, 4), (96, 3), (48, 2), (53, 1), (26, 4), (31, 3), (68, 2),
(91, 1)]
>
> >Specifically, I'm wondering if this is a good algorithm for
> >weighted voting. Essentially a vote is weighted by the number of
> >votes it counts as. I realize that this is an extremely simple
> >algorithm, but I was wondering if anyone had suggestions on how to
> >improve it.
>
> I snipped most of your code.  I don't see anything wrong with your
> overall approach.  I will make one suggestion: watch out for
> DivisionByZero.
>
>     try:
>         score = sum_of_votes / num_of_votes
>     except ZeroDivisionError:
>         score = float('nan')
>
> In your example data, all of the weights were integers, which means
> that a simple mean function would work, as well, if you expanded the
> votes to an alternate representation:
>
>   votes = [72, 72, 72, 72, 96, 96, 96, 48, 48, 53, 26, 26, 26, 26,
>            31, 31, 31, 68, 68, 91]
>
> But, don't bother!
>
> Your function can handle votes that have a float weight:
>
>   >>> weight([(4, 1.3), (1, 1),])
>   2.695652173913044
>
> Have fun!
>
> -Martin
>
> --
> Martin A. Brown
> http://linux-ip.net/

Thanks Martin!

I'll add the check for division by zero. Didn't think about that. I think
I'm going to sanitize input anyways, but always better to be safe than
sorry.