dec2rom_rom2dec.py

# Por Luis Mex
# funciones sencillas para numeros arabicos a romanos y viceversa


def arab2rom(val):

        rabc=['I','II','III','IV','V','VI','VII','VIII','IX',
                  'X','XX','XXX','XL','L','XC','C','CC','CCC'
              ,'CD','D','CM','M','MM','MMM','MV_','V_']

        abc=[1,2,3,4,5,6,7,8,9,10,20,30,40,50,90,100,200,300,400,
        500,900,1000,2000,3000,4000,5000]

        string=''
        i=0
        val_act=val
        if val_act > 5000 :
                print " el valor supera la gramtica"
                exit()
        while True:
                if (val_act == 0):
                        break
                else:
                        for j in range(0,len(abc)):
                                if (val_act < abc[j]):
                                        val_tmp=-abc[j-1]+val_act
                                        val_act=val_tmp
                                        i=j
                                        string+=rabc[j-1]
                                        break
                                elif (val_act >= abc[len(abc)-1]):
                                                #print "True"
                                                val_tmp=-abc[j-1]+val_act
                                                val_act=val_tmp
                                                i=j
                                                string+=rabc[j-1]
                                                break
        return string

def rom2arab(string):

        rabc=['I','II','III','IV','V','VI','VII','VIII','IX',
                          'X','XX','XXX','XL','L','XC','C','CC','CCC'
                          ,'CD','D','CM','M','MM','MMM','MV_','V_']

        abc=[1,2,3,4,5,6,7,8,9,10,20,30,40,50,90,100,200,300,400,
                500,900,1000,2000,3000,4000,5000]

        num=[]

        for i in range(0,len(string)):
                for j in range(0,len(abc)):
                        if string[i]==rabc[j]:
                                num.append(abc[j])

        for j in range(0,len(num)-1):
                for i in range(j,j+1):
                        if num[i] < num[i+1]:
                                num[i]=-num[i]

        return sum(num)



val=45
val_r='XLV'
f=arab2rom(val)
g=rom2arab(val_r)
print f,g