generic number class builder

generic_number.py

# For this codewar question: https://www.codewars.com/kata/54baad292c471514820000a3

import math


def create_number_class(bases):
    base = len(bases)

    def __init__(self, value):
        self.value = value

    def to_int(self):
        _sum = 0
        for i, ch in enumerate(self.value):
            _sum += bases.index(ch) * (self.base ** (len(self.value) - i - 1))
        return _sum

    @classmethod
    def from_int(kls, int_):
        if int_ == 0:
            return kls.bases[0]
        digits = math.floor(math.log(int_)/math.log(kls.base)) + 1
        chars = []
        value = int_
        for i in range(digits):
            index = value // (kls.base ** (digits - i - 1))
            chars.append(kls.bases[index])
            value -= index * (kls.base ** (digits - i - 1))
        return kls(''.join(chars))

    def convert_to(self, klass):
        return klass.from_int(self.to_int())

    def __str__(self):
        return self.value

    def __add__(self, obj):
        return self.__class__.from_int(self.to_int() + obj.to_int())

    def __sub__(self, obj):
        return self.__class__.from_int(self.to_int() - obj.to_int())

    def __floordiv__(self, obj):
        return self.__class__.from_int(self.to_int() // obj.to_int())

    def __mul__(self, obj):
        return self.__class__.from_int(self.to_int() * obj.to_int())


    klass = type(
        'klass', (object, ),
        dict(
            base=base,
            bases=bases,
            from_int=from_int,
            to_int=to_int,
            convert_to=convert_to,
            __init__=__init__,
            __add__=__add__,
            __sub__=__sub__,
            __mul__=__mul__,
            __floordiv__=__floordiv__,
            __str__=__str__,
        ),
    )
    return klass