Most concise Python radix function using functional constructions?
From my perspective, I'd say use the generator. It's concise and easily readable to most people familiar with Python. I'm not sure if you can do this in a functional sense easily without recreating some of the toolkit of functional programming languages. For example, if I wanted to do this in Haskell (which I am by no means an expert in, so this may be a horrible way for all I know), I'd do something like:

radix :: Int -&gt; Int -&gt; [Int]
radix x n = takeWhile (&gt; 0) $ iterate (\z -&gt; z `div` n) x


You can certainly recreate takeWhile and iterate, however, this only works due to lazy evaluation. The other option is, as you've said, using log and basically recreating scanl:

def scanl(f, base, l):
    yield base
    for x in l:
        base = f(base, x)
        yield base

def radix(n, r):
    return scanl(operator.__floordiv__, n, (r for x in range((int)(log(n, r)))))


So my answer is going to be "No" (predicated on the fact that someone smarter than me will probably find a way). However, unless you are playing Code Golf, I'd again suggest sticking with the generator version.