title: Getting Attrbute error _exit_ when use "with" keyword
body: <p>I have passed <code>.csv</code> file to post request,</p>
  
  <pre><code>input_file = data.get('file', None)
  with input_file as datasheet:
          header = datasheet.readline()
  </code></pre>
  
  <p>Always I am getting error on second line. Also my file type is <code>Unicode</code> thats why it again giving error on third line for <code>readline()</code></p>