编写Python程序：给定一个整数，将其转为罗马数字。输入确保在 1 到 3999 的范围内

def change(text):
    
    num=int(text)
    
    # 数组内数据位置不要改，不然就不能从高位开始对比
    checkNum = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
    str =["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX","V", "IV", "I"]
    roman = ""
    i = 0

    #对比完，减去已对比数组，对比数组下个值
    while (num != 0) :
        if (num >= checkNum[i]):
            num -= checkNum[i]
            roman += str[i]
        else:
            i+=1

    return roman

def main():
    text = input("输入整数")

    print(change(text))

main()