title: Stopping form submission on page refresh
body: <p>I have a form with Flask/Python/Html</p>
  
  <p>When the form is submitted it is routed to another page where it gives a confirmation such as "Form submission success!"</p>
  
  <p>However if I refresh the page it will submit the content again, so I potentially could end up with duplicate data.</p>
  
  <p>Is there a way to prevent this?</p>
  
  <p>HTML</p>
  
  <pre><code>&lt;form action="{{ url_for('submitForm') }}" method="post"&gt;
  &lt;input name='user_input'&gt;
  &lt;button type='submit'&gt;Submit&lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>Python/Flask</p>
  
  <pre><code>app.route('/submitForm', methods=['POST'])
  def submitForm():
      data = request.form['user_input']
      some_list.append(data)
      return 'Form submitted'
  </code></pre>