title: Python 2.7 TypeError: Unsupported operand type(s) for %:'None type' and str
body: <p>I've got an issue where when i try to print 'filename' i get this error</p>
  
  <pre><code>line 101, in purchase_code_fn
      print("QR Code Created: %s") %(filename)
  TypeError: unsupported operand type(s) for %: 'NoneType' and 'str'
  </code></pre>
  
  <p>Below is the offending function.</p>
  
  <pre><code>def purchase_code_fn():
      count=+1
      name = raw_input("Name: ")
      email_prompt = raw_input("Please enter your email address: ")
      userid = uuid.uuid4()
      filename = (str(email_prompt)+str(count))
      print("QR Code Created: %s") %(filename)
      qr_code_fn(email_prompt, userid)
  </code></pre>
  
  <p>A pointer in the right direction would be fantastic. </p>
  
  <p>Cheers!</p>