stuff.py

class Solution(object):
    def intToRoman(self, num):
        """
        :type num: int
        :rtype: str
        """
        
        conversion_map = {
          1: "I",
          5: "V",
          10: "X",
          50: "L",
          100: "C",
          500: "D",
          1000: "M"
        }
        subtraction_instances = {
          4: "IV", 
          9: "IX",
          40: "XL", 
          90: "XC", 
          400: "CD", 
          900: "CM"
        }
        numerics = sorted(conversion_map.keys(), reverse=True)
        
        leftover = num
        place = 10
        built_str = ""
        
        while leftover > 0:
          processed = leftover % place
          
          subtraction_instance = subtraction_instances.get(processed)
          if subtraction_instance:
            built_str = subtraction_instance + built_str
          else:
            for i, numeric in enumerate(numerics):
              if processed >= numeric:
                if numeric == 1:
                  built_str = "".join(
                    "I" 
                    for _ in range(processed)
                  ) + built_str
                else:
                  built_str = "{0}{1}".format(
                    conversion_map.get(numeric),
                    "".join(
                      conversion_map.get(numerics[i+1]) 
                      for _ in range(processed-numerics)
                    )
                  ) + built_str
                  
                break
          
          leftover -= processed
          place *= 10
          
        return built_str