Leetcode (Python): Integer to Roman

Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999.

Solution:

class Solution:
    # @return a string
    def intToRoman(self, num):
        sol =[]
        sol.append(self.digitToRoman(num/1000, ' ', ' ','M'))
        sol.append(self.digitToRoman((num/100)%10, 'M', 'D', 'C'))
        sol.append(self.digitToRoman((num/10)%10, 'C', 'L','X'))
        sol.append(self.digitToRoman(num%10, 'X', 'V', 'I'))
        return ''.join(sol)
        
    def digitToRoman(self, num, charTen, charFive, charOne):
        char=[]
        if num>8:
            for i in range(num,10):
                char.append(charOne)
            char.append(charTen)
        elif num>=5:
            char.append(charFive)
            for i in range(5,num):
                char.append(charOne)
        elif num>3:
            for i in range(num,5):
                char.append(charOne)
            char.append(charFive)
        else:
            for i in range(0,num):
                char.append(charOne)
        return ''.join(char)