Two functions that convert a number in a Roman numeral.

to_roman.py

# Author: Bismarck Gomes <bismarckgomes@gmail.com>

def to_roman(num):
    d = ['I', 'V', 'X', 'L', 'C', 'D', 'M']
    roman = d[0] * num

    for i, v, x in zip(d[::2],d[1::2], d[2::2]):
        roman = roman.replace(5*i, v).replace(4*i, i+v)
        roman = roman.replace(2*v, x).replace(v+i+v, i+x)

    return roman

def to_roman2(num):
    roman = ''
    d = [('I', 1),  ('IV', 4),   ('V', 5),   ('IX', 9), 
         ('X',10),  ('XL', 40),  ('L', 50),  ('XC', 90),
         ('C',100), ('CD', 400), ('D', 500), ('CM', 900),
         ('M', 1000) ]

    for t, n in d[::-1]:
        q, num = divmod(num, n)

        roman += q*t
        
    return roman

if __name__ == '__main__':
    num = 200
    func = to_roman#2
    rows, cols = 5, 8
    ini = 1
    while (ini < num):
        for row in range(ini,ini+rows):
            for n in range(row, ini+rows*cols, rows):
                if (n > num): break
                print "%3d  %-10s" % (n, func(n)),
            print
        print
        ini += rows*cols