You can configure settings config file for customizing Kay application’s behavior.
This attribute has different effect on local dev server and appengine server.
Local environment:
If DEBUG is set to True, werkzeug’s debugger will come up on any uncaught exception. Otherwise, it just displays 500 error, and tracebacks will be printed on console.
Server environment:
If DEBUG is set to True, it displays tracebacks on your browser on any uncaught exception. Otherwise, it displays a simple error message to end users, and tracebacks will be sent to administrators by email.