roman_numerals.py

def checkio(data):
    soln = {
        1: 'I',
        4: 'IV',
        5: 'V',
        9: 'IX',
        10: 'X',
        40: 'XL',
        50: 'L',
        90: 'XC',
        100: 'C',
        400: 'CD',
        500: 'D',
        900: 'CM',
        1000: 'M'
        }
    
    result = ''
    for number in reversed(sorted(list(soln.keys()))):
        result += soln[number] * (data // number)
        data %= number
    return result