## Write a class that, when given a string, will return an uppercase string with each letter shifted forward in the
# alphabet by however many spots the cipher was initialized to.
from string import ascii_uppercase
class CaesarCipher(object):

    def __init__(self, shift):
        self.shift = shift

    def encode(self, str_):
        self.str_ = str_
        result = ''
        for i in range(len(str_)):
            if str_[i].upper() in ascii_uppercase:
                try:
                    result += ascii_uppercase[ascii_uppercase.index(str_[i].upper()) + self.shift]
                except IndexError:
                    result += ascii_uppercase[(ascii_uppercase.index(str_[i].upper()) \
                                               + self.shift) - len(ascii_uppercase)]
            else:
                result += str_[i]
        return result


    def decode(self, str_):
        self.str_ = str_
        result = ''
        for i in range(len(str_)):
            if str_[i].upper() in ascii_uppercase:
                try:
                    result += ascii_uppercase[ascii_uppercase.index(str_[i].upper()) - self.shift]
                except IndexError:
                    result += ascii_uppercase[len(ascii_uppercase) \
                                              - (ascii_uppercase.index(str_[i].upper()) + self.shift)]
            else:
                result += str_[i]
        return result






c = CaesarCipher(5)
print(c.encode("CodeWars"))
print(c.decode('HTIJBFWX'))