Integers to Numerals

int_to_numeral.py

class Solution:
    I = 'I'
    V = 'V'
    X = 'X'
    L = 'L'
    C = 'C'
    D = 'D'
    M = 'M'
    def intToRoman(self, num):
        """
        :type num: int
        :rtype: str
        """
        self.generate_int_array(num)
        return self.thousands() + self.hundreds() + self.tens() + self.units()
      
    def generate_int_array(self, num):
        self.int_array = []
        while num > 0:
            self.int_array.append(num % 10)
            num //= 10
    
    def thousands(self):
        if len(self.int_array) < 4:
            return ''    
        return  self.M * self.int_array[3]
    
    def hundreds(self):
        return self.convert_digit_to_symbol(2, self.C, self.M, self.D)   
    
    def tens(self):
        return self.convert_digit_to_symbol(1, self.X, self.C, self.L)  
    
    def units(self):
        return self.convert_digit_to_symbol(0, self.I, self.X, self.V)
      
    def convert_digit_to_symbol(self, cardinality, symbol, higher, mid):
        if len(self.int_array) < (cardinality + 1):
            return ''
        val = self.int_array[cardinality]
        if val == 9:
            return symbol + higher
        if val >= 5:
            return mid + (symbol * (val - 5))
        if val == 4:
            return symbol + mid
        return symbol * val