파이썬-Base64 Encode/Decode

#!/usr/bin/python
# -*- coding: cp949 -*-

import base64

def main():

    print '======================'
    print '1 : base64 encoding'
    print '2 : base64 decoding'
    print '======================'
    print 'select number :',

    select = raw_input()
    
    if select == '1':
        b64_encode()
    elif select == '2' :
        b64_decode()
    else:
        ex()
   
def b64_encode():
    print 'base64로 인코딩 할 값을 적어주세요'
    print '==>  ',
    b64str=raw_input()

    encode_str = base64.encodestring(b64str)
    print 'result ==>  ', encode_str

    main()

def b64_decode():
    print 'base64로 디코딩 할 값을 적어주세요'
    print '==>  ',
    b64str=raw_input()

    decode_str = base64.decodestring(b64str)
    print 'result ==>  ', decode_str

    main()

def ex():
    pass

main()