input: def int_to_Roman(number: int) -> str:
      """ Convert a given number into its Roman numeral form.
      >>> int_to_Roman(15)
      'XV'
      >>> int_to_Roman(1994)
      'MCMXCIV'
      """
      val = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
      syb = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"]
      roman_num = ''
      i = 0
      while number > 0:
          for_val = number // val[i]
          roman_num += syb[i] * for_val
          number -= val[i] * for_val
          i += 1
      return roman_num
output:     val = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
      syb = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"]
      roman_num = ''
      i = 0
      while number > 0:
          for_val = number // val[i]
          roman_num += syb[i] * for_val
          number -= val[i] * for_val
          i += 1
      return roman_num