roman-recur.py

#!/usr/bin/env python

import sys

table = (
    ("M", 1000),
    ("D", 500),
    ("CD", 400),
    ("C", 100),
    ("L", 50),
    ("XL", 40),
    ("X", 10),
    ("IX", 9),
    ("V", 5),
    ("IV", 4),
    ("I", 1),
)

def roman(i, table=table):
    if i == 0: return ""
    if table == (): return ""
    (symbol, value) = table[0]
    quotient = i / value
    if quotient > 0:
        result = quotient * symbol
    else:
        result = ""
    return result + roman(i - (quotient * value), table[1:])

for i in [1,2,3,4,5,6,7,8,9,10,11,14,15,16,49,50,51]:
    print "roman(%s): %s" % (i, roman(i))