ascii 더하기 빼기 연산 (문자열)

 

aaa = ["VkduhgRemhfw1surwrw|sh", "Gdwh1surwrw|sh"]
bb = ""

for x in range(0,len(aaa)):
    for a in range(0,len(aaa[x])):
        bb = bb + chr(ord(aaa[x][a])-3)
    print bb
    bb = ""