利用字符移位进行密码破解

def shift_char(c, shift):
    if c.islower():
        return chr(((ord(c)-97+shift)%26)+97)
    elif c.isupper():
        return chr(((ord(c)-65+shift)%26)+65)
    else:
        return c # don not shift non-letters

def caesar_cipher(s, shift):
    m = ""
    for c in s:
        m += shift_char(c, shift)
    return m

text = "Thank You!"  # the die has been cast
print text, "becomes", caesar_cipher(text, 6)