Convert to roman numeral

roman.py

from itertools import repeat

def to_roman(n):
    return (''.join(repeat('I', n))
            .replace('IIIII', 'V')
            .replace('VV', 'X')
            .replace('XXXXX', 'L')
            .replace('LL', 'C')
            .replace('CCCCC', 'D')
            .replace('DD', 'M')
            .replace('VIIII', 'IX')
            .replace('IIII', 'IV')
            .replace('LXXXX', 'XC')
            .replace('XXXX', 'XL')
            .replace('DCCCC', 'CM')
            .replace('CCCC', 'CD'))