Convert integer to Roman number literals

int2roman.py

I2R = {1: 'I', 2: 'II', 3: 'III', 4: 'IV', 5: 'V', 9: 'IX', 10: 'X', 20: 'XX', 30: 'XXX', 40: 'XL', 50: 'L', 90: 'XC', 100: 'C', 200: 'CC', 300: 'CCC', 400: 'CD', 500: 'D', 900: 'CM', 1000: 'M', 2000: 'MM', 3000: 'MMM'}
Candidates = [3000, 2000, 1000, 900, 500, 400, 300, 200, 100, 90, 50, 40, 30, 20, 10, 9, 5, 4, 3, 2, 1]

def int2roman(num: int) -> str:
    roman = ''
    while num > 0:
        d = next(x for x in Candidates if num >= x)
        num -= d
        roman += I2R[d]
    return roman