zlacker

>>jstrie+(OP)
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+Wc

    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+Ke
The problem statement said that the input would be natural numbers.