attributedict: dictionary whose keys are also attributes

>>> class attributedict(dict):
...    def __init__(self, *a, **kw):
...       self.__dict__ = self
...       dict.__init__(*a, **kw)
...

>>> ad = attributedict()

>>> ad["one"] = 1

>>> ad.one

1

>>> ad.two = 2

>>> ad["two"]

2
>>> attributedict(three=3).three
3


Edit: unsurprisingly, I'm not the first one to come up with this construct.  Here is one example that predates my post by 5 years: http://code.activestate.com/recipes/361668/