title: How to validate URL parameters in Flask
body: <p>This is my first application using Flask and Python.</p>
  
  <p>I am using below URL format to send a POST request from Arduino to the flask application running on Pythonanywhere server instance.</p>
  
  <p>Valid POST request: 3 URL parameters
  <a href="http://voyagers.pythonanywhere.com/senddata?node=1234&amp;lat=18.5580&amp;lng=73.8075" rel="nofollow noreferrer">http://voyagers.pythonanywhere.com/senddata?node=1234&amp;lat=18.5580&amp;lng=73.8075</a></p>
  
  <p>I need to block the request from further processing by validating the URL in some form. I want this to secure my app from un-authenticated POST requests.</p>
  
  <p>Say something like this:Anything more than 3 URL Parameters
  <a href="http://voyagers.pythonanywhere.com/senddata?node=324&amp;lat=18.5580&amp;lng=73.8075&amp;a=c&amp;a=d" rel="nofollow noreferrer">http://voyagers.pythonanywhere.com/senddata?node=324&amp;lat=18.5580&amp;lng=73.8075&amp;a=c&amp;a=d</a></p>
  
  <p>How can I achieve this in Flask ?</p>
  
  <p>Also suggest , If there is any better way which could be used to secure application from un-authorised requests. </p>