A language for describing graphs

[Basu]

I've been doing some research involving Lindenmayer systems and in the process have come to looking at graphs. Unfortunately I know only a small amount of graphs as part of my 2nd CS course at college. I have a basic of what they are and some algorithms (Prim, Djikstra). I've been building a small library for graphs in Python, both because Python doesn't have native graphs and also because I want to learn more about graphs. I know that there are some 'standard' implementations of graphs (matrices, lists etc) but I was wondering if there is some standard implementation-independent language for describing graphs and graph algorithms (in the way that lambda calculus is a language for describing computation via functions). I know this isn't a particularly clear request, partially because I'm not very sure about what I'm looking for myself, so any contributions would be welcome.

[rdrake]

AT&T created Graphviz. Basically you write a simple text file in the Dot language and it processes it to create a pretty graph. Check out the examples, you can do some pretty complicated things.

Oh, and Graphviz has bindings for numerous languages so you can generate graphs in Python even .

[apomb]

If you want something like that as well, check outcacti. it uses RRD tool to graph any sort of data you can think of.
It also has bindings for many languages, i mostly use perl scripts to populate the databases, but you could use python, ruby, hell, you could even use turing if you really wanted.

[btiffin]

Check out R. http://cran.r-project.org/

If you do; after installing and starting up R, try
> demo(graphics)

If you want to go all "mainstream" check out GNUPlot. http://www.gnuplot.info/

And after that, check out Ch. The free student edition offers a stats and plotting layer.
http://www.softintegration.com/

But check out R, it's manly; GNUPlot is for weenies that can't handle real statistics. (Kidding. GNUPlot is pretty cool too).
Python has a GNUPlot interface. http://gnuplot-py.sourceforge.net/

Cheers
Edits; Added the gnuplot.py link.