romanos.py

"""
romanos.py - arabicos para romanos


    >>> ara2rom(1)
    'I'
    >>> ara2rom(2)
    'II'
    >>> ara2rom(3)
    'III'
    >>> ara2rom(4)
    'IV'
    >>> ara2rom(5)
    'V'
    >>> ara2rom(6)
    'VI'
    >>> ara2rom(7)
    'VII'
    >>> ara2rom(8)
    'VIII'
    >>> ara2rom(9)
    'IX'
    >>> ara2rom(10)
    'X'
    >>> ara2rom(11)
    'XI'
    >>> ara2rom(12)
    'XII'
    >>> ara2rom(14)
    'XIV'
    >>> ara2rom(15)
    'XV'
    
"""

def unidade(a):
    pass

def ara2rom(a):
    dic = {
        4 : 'IV',
        9 : 'IX',
        14: 'XIV'
    } 
    if a in dic:
        return dic[a]
    
    elif a <= 20:
        one = a % 5
        five = a / 5 
        ten = a / 10
        if a >= 10 :
            five = 0
            if a == 15:
                five = 1
        return 'X' * ten + 'V' * five + 'I' * one