Converting an Integer to a String in Any Base

abcnum_converter.py

import string

# http://interactivepython.org/runestone/static/pythonds/Recursion/pythondsConvertinganIntegertoaStringinAnyBase.html

class AbcNumCoverter:
    chars = string.digits + string.ascii_lowercase
    base = len(chars)

    @classmethod
    def to_str(cls, n):
       if n < cls.base:
          return cls.chars[n]
       else:
          return cls.to_str(n // cls.base) + cls.chars[n % cls.base]

    @classmethod
    def to_num(cls, s):
        n = 0
        for index, char in enumerate(s[::-1]):
            n += cls.chars.index(char) * cls.base ** index
        return n


for x in range(100):
    s = AbcNumCoverter.to_str(x)
    n = AbcNumCoverter.to_num(s)
    print(x, s, n)