On 16/07/2008, Michiel Overtoom <[EMAIL PROTECTED]> wrote:
> Lauren wrote...
> > Based on some research I've done, I think I want my data structure to
> > be a series of lists within lists:
> # start of example
>
> # this example uses a hierarchy of three levels: 1) continent, 2)
> country/state, and 3) city
> geo=[
> "australia",
> "europe",[
> "spain",
> "germany",
> "belgium",
> ],
> "america",[
> "california",[
> "los angeles",
> "san francisco",
> "berkeley"
> ],
> "texas",
> "utah"
> ],
> "asia"
> ]
I think the normal way of representing a tree in python would be as
(value, children) tuples.
In this case, you would have:
geo = [('australia', []), ('europe', [('spain', []), ('germany', []),
('belgium', [])]),
('america', [('california', [('los angeles', []), ('san
francisco', [])]),
('texas', [('detroit', [])])]),
# etc
]
This lets you avoid messy isinstance testing to figure out if you've
got a value or a list of children.
(admittedly, it can be hard to keep track of the brackets, but good
indentation and a monospaced font should help out)
--
John.
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
