Data structure recommendation?

[bearophileHUGS at lycos.com]

Few more notes on the code:

You may use the @property in such situations (or you may just use
attributes, dropping the property). Note that Python doesn't inline
functions calls like Java HotSpot does quite often.
    def __children(self):
        raise NotImplementedError()
    children = property(__children)
==> (not tested!)
    @property
    def __children(self):
        raise NotImplementedError()


If the profiling shows this is s slow, and it's used on lot of items,
there are faster O(1) algorithms for this, like this one:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/466330
    @staticmethod
    def determine_median(numbers):
        return sorted(numbers)[ len(numbers) / 2  ]

I have seen you use lot of double underscores (I think one may often
suffice, but usually two aren't a problem):
    def __children(self):

Stripped of comments, docstrings, and empty lines the code is just 280
lines long (it's 1498 with them!), so a translation doesn't seem too
much work (expecially if the original version was Java). The code seem
really well commented, organized, etc. And I like it, it looks better
than 90+% of the commercial Python code I see :-)

Bye,
bearophile