title: Django check if server is already running
body: <p>I am on Windows, and run my Django server via <code>manage.py runserver 8001</code>. When I have already running server and enter the mentioned command again, it starts another server listening the same (8001) port. What I would like to do is to determine if server is already running and stop the execution of the command, or stop the running server and then run the new server.</p>
  
  <p><strong>UPDATE:</strong>
  I need to do the described things automatically. Throwing an error is also OK.
  But why <code>runserver</code> command is not throwing an error, if the port is already busy?? That's a standard behavior of platforms that I have experience with (Java Tomcat server, PHP) and also on Ubuntu with Django, as  <a href="https://stackoverflow.com/questions/880239/how-to-clear-the-port-when-restarting-django-runserver">this question</a> clarifies. </p>