Dictionary that uses regular expressions

[Corey Coughlin]

Hey, cool code, I wrote a dictionary-keyed dictionary a while back to
get something like the same functionality, basically I wanted an
n-dimensional database type object and a dictionary with a dictionary
key seemed like the way to go, but keeping the keys as strings and
using regexps to find unique objects seems like a smart way to go. 
The code is certainly cleaner, although I'm sure my version is far
from optimal (or pythonic, for that matter.)  Thanks for sharing!