title: Why will my variable not change when placed in a payload?
body: <p>I am trying to get a payload value "productid" to +1. But when I use productid+1 the productid variable does not change?</p>
  
  <p>When I run the script the product id stays as "7367" when it should have changed to "7368"</p>
  
  <pre><code>productid=7367
  
  headers = {
      "Host": "www..co.uk",
      "Connection": "keep-alive",
      "Content-Length": "121",
      "Cache-Control": "max-age=0",
      "Origin": "http://www..co.uk",
      "Upgrade-Insecure-Requests": "1",
      "User-Agent": "Chrome/57.0.2987.133 Safari/537.36",
      "Content-Type": "application/x-www-form-urlencoded",
      "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
      "Accept-Encoding": "gzip, deflate, br",
      "Accept-Language": "en-US,en;q=0.8",
      }
  
  payload = {
      "attributes":"",
      "product_quantity":"1",
      "submit":"",
      "product_id":productid+1,
      "show_image_":"0",
  
  }
  
  print ("ProductID:"), productid
  </code></pre>