title: Generating own key with Python Fernet
body: <pre><code>from cryptography.fernet import Fernet
  
  import base64
  # Put this somewhere safe!
  key = Fernet.generate_key()
  
  f = Fernet()
  token = f.encrypt(b"A really secret message. Not for prying eyes.")
  token
  print f.decrypt(token)
  </code></pre>
  
  <p>How can I generate my own key instead of <code>fernet.genrate_key()</code>? </p>