Integer to Roman number literals; O(1) solution for constraint 0 < num < 4000

int2roman.py

def int2roman(num: int) -> str:
    ONES = ["","I","II","III","IV","V","VI","VII","VIII","IX"]
    TENS = ["","X","XX","XXX","XL","L","LX","LXX","LXXX","XC"]
    HUNDREDS = ["","C","CC","CCC","CD","D","DC","DCC","DCCC","CM"]
    THOUSANDS = ["","M","MM","MMM"]
    return THOUSANDS[num//1000] + HUNDREDS[(num%1000)//100] + TENS[(num%100)//10] + ONES[num%10];