title: simple encrypt/decrypt lib in python with private key
body: <p>Is there a simple way to encrypt/decrypt a string with a key?</p>
  
  <p>Something like:</p>
  
  <pre><code>key = '1234'
  string =  'hello world'
  encrypted_string = encrypt(key, string)
  decrypt(key, encrypted_string)
  </code></pre>
  
  <p>I couldn't find anything simple to do that.</p>