[Tutor] advice on creating and working with a complex data structure

[Alan Gauld]

"Serdar Tumgoren" <zstumgoren at gmail.com> wrote 

> I'm working with a database of campaign finance filings, and I'm
> trying to create a data structure that captures the fact that:
>  - there can be multiple races
>  - races can have multiple candidates
>  - candidates can have multiple campaign committees
>  - campaign committees can file multiple reports

Have you considered using classes? This looks like a fairly 
natural fit for race, candidate, committee and maybe report 
casses

> I'm trying to pull these records from a database and output them to an
> HTML file in sorted order.

Each class could have a render method that retuirns 
an HTML fragment as a  string...

> Once I've created the data object,  I'd like to group the output by
> race, party, candidate, committee and filing, so that when I output in
> my template, it appears like this:

You could provide support for a sort method that would
do the grouping for yopu...

> I've been looking at Cookbook examples that rely on the setdefault
> method to add key:value pairs to a dictionary, but I wasn't sure how
> to implement that approach for a data structure with so many layers of
> nesting.

One level at a time!
But with classes there would be less nesting and more relatinships

> * Is the best approach to create some type of a Race class that can
> store all these varying data points for each race?

I think you want a lot more than a Race class, see above.


> * Should I be using some type of recursive function to handle all the
> levels of nesting?

Probably not, a simple inter-bject relationship will make traversal 
much easier

> And of course, please let me know if there's a simpler approach I'm
> overlooking that would meet my requirements.

I think creating more objects and getting each object to handle 
fetching the stuff from its next level down would be simpler

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/