zlacker

By using a do-while loop, you don't have to handle the special case of zero (although one could argue that the do-while loop is the special handling for zero). Python does not have such a loop, so you need to do an infinite loop with an explicit break and I know some people recoil in horror at the sight of such code.

    def digitlength(n):
        digits = 0
        while True:
            digits += 1
            n /= 10
            if n == 0:
                return digits

>>gnuvin+(OP)

    def digitlength(n):
        digits = 1
        while (n > 9):
            digits += 1
            n /= 10
        return digits

Also may want to set n = abs(n) in the beginning, in case n is negative.

>>a-niko+O1
The problem statement said that the input would be natural numbers.

>>gnuvin+T1
Wait, do natural numbers include zero? evil grin

>>lifthr+A8
No support for that in Sloane's. https://oeis.org/A000027

>>lifthr+A8
I looked up wikipedia which says there's no conclusive definition.

>>chopin+xJ
The joke is that, if you don't need to check if the input is negative because it is not a natural number, you can also choose a definition of the natural number without zero to avoid special casing it at all.