Convert an Integer to a String in any baseΒΆ

Converting an Integer to a String in any base.
def to_string(N, base):

    hex_nums = "0123456789ABCDEF"

    if N < base:
        return hex_nums[N]
    else:
        return to_string(N // base, base) + hex_nums[N % base]

print(to_string(2835, 16))    # B13