integers to roman numerals

convert.py

ordered = [
    1, 5, 10, 50, 100, 500, 1000
]
mapping = {
    1: "I",
    5: "V",
    10: "X",
    50: "L",
    100: "C",
    500: "D",
    1000: "M",
    4: "IV",
    9: "IX",
    40: "XL",
    90: "XC",
    400: "CD",
    900: "CM"
}
def toRoman(n):
    ## only takes in numbers with 1 deciding character; followed by leading zeroes
    r = ""
    if n in mapping:
        return mapping[n]
    else:
        index = 0
        for x in ordered:
            if n < x:
                break
            index += 1
        index -= 1
        
        multiplierFactor = 0
        while True:
            multiplierFactor += 1
            if ordered[index] *multiplierFactor > n:
                multiplierFactor -= 1
                break
        
        foundN = mapping[ordered[index]] *(multiplierFactor)
        r += foundN
        if n - ordered[index] *multiplierFactor > 0:
            nn = n - ordered[index] *multiplierFactor
            a = toRoman(nn)
            r += a
        return r
def intToRoman(num: int):
    d = ""
    
    index = -1
    for i in range(len(str(num)) -1, -1, -1):
        index += 1
        value = int(str(num)[i]) *(10 **index)
        if value == 0:
            continue
        
        roman = toRoman(value)
        d = "{}{}".format(roman, d)
    return d

if __name__ == "__main__":
    while True:
        inp = 0
        while True:
            prompt = input("Integer to convert to roman numerals: ")
            if prompt.isdigit():
                inp = int(prompt)
                break
            else:
                print("Invalid input; try again.\n")
        print("Roman numeral: {}\n".format(intToRoman(inp)))