Display integers using roman numerals.

roman.py

#!/usr/bin/env python3
# Run `import roman` then you can use the function `roman.rnumeral()`.

def rnumeral(n):
	
    if n >= 4000:
        print('The largest number that can be represented in roman numerals is 3999.')
        return
    if n <= 0:
        print('Choose a positive number.')
        return

    num = str(n)
    Rom = ('I', 'V', 'X', 'L', 'C', 'D', 'M')
    res = ''

    count = (len(num)-1)*2
    for c in num:
        M = int(c)
        if (M > 0 and M < 4):
            res = res + M*Rom[count]
        if (M >= 4 and M <= 5):
            res = res + (5 % M)*Rom[count] + Rom[count+1]
        if (M > 5 and M < 9):
            res = res + Rom[count+1] + (M % 5)*Rom[count]
        if (M >= 9 and M <= 10):
            res = res + (M % 2)*Rom[count] + Rom[count+2]
        count = count - 2

    return res