Handle the error

example.py

@@ -46,6 +46,7 @@ def example():
     if 'gateway' in state:
         gateway = wideq.Gateway.load(state['gateway'])
     else:
+        print('Discovering gateway servers.')
         gateway = wideq.Gateway.discover()
 
         state['gateway'] = gateway.dump()
@@ -65,16 +66,22 @@ def example():
         session = wideq.Session.load(auth, state['session'])
         devices = None
     else:
+        print('Starting session.')
         session, devices = auth.start_session()
 
         state['session'] = session.dump()
         save_state(state)
 
+    try:
         # Request a list of devices, if we didn't get them "for free"
         # already by starting the session.
         if not devices:
             devices = session.get_devices()
 
+    except wideq.NotLoggedInError:
+        print('Session expired.')
+        return
+
     print_devices(devices)