title: decrypt a column in a dataframe Fernet (Token must be bytes)
body: <p>I am looking to decrypt a column of csv file that I have encrypted using the same key I have used to encrypt that column when I wrote that file. Here is what I am doing :</p>
  <pre><code> with open('thekey.key', 'rb') as mykey:
            key = mykey.read()
  
   f = Fernet(key)
  
   df =pd.read_csv('codedfile.csv')
  
   f.decrypt(df['Password'])
  </code></pre>
  <p>I am sure that happens because the values type inside Password are strings (although it looks like <code>b'nqjnnxqwa</code>), but I do not know how to change them into bytes.</p>