4a. Define a Python function called digits that, on input a positive integer NN and a positive integer bb, returns a tuple consisting of the digits of NN written in base bb, from left to right. For example, if N = 327N=327 and b = 10b=10, you should return (3,2,7).

4b. In terms of your answer to part a, write a list comprehension in terms of the variables `b` and `N` to find all integers from $1$ to $N$ (inclusive) which are multiples of the sum of their base-$b$ digits.