Why my code prints others characters? cipher
<p>I want print only letters but it's prints special characters of ASCII. My code:</p>

<pre><code>import string
def caesar(shift):
    alphabet = string.ascii_lowercase + string.ascii_uppercase
    dict={}
    emptylist=[]
    int(shift)
    for x in alphabet:
        emptylist.append(x)
        code = ""
        for letters in emptylist:
            code = chr(ord(letters) + shift)
            dict[letters]=code
    return dict
caesar(12)
</code></pre>

<p>My output:</p>

<blockquote>
  <p>'m': 'y', 'l': 'x', 'o': '{', 'n': 'z', 'q': '}', 'p': '|', 's': '\x7f', 'r': '~', 'u': '\x81', 't': '\x80', 'w': '\x83', 'v': '\x82', 'y': '\x85', 'x': '\x84', 'z': '\x86'</p>
</blockquote>

<p>Correct output:</p>

<blockquote>
  <p>'m': 'y', 'l': 'x', 'o': 'a', 'n': 'z', 'q': 'c', 'p': 'b', 's': 'e', 'r': 'd', 'u': 'g', 't': 'f', 'w': 'i', 'v': 'h', 'y': 'k', 'x': 'j', 'z': 'l'</p>
</blockquote>
