WebAgg: flush stdout after printing, redirect "stopped" message to stderr

vmarkovtsev · vmarkovtsev · commit 5a7bb98b2974 · 2014-11-07T16:31:42.000+03:00
Without flushing, the message can be displayed too late. KeyboardInterrupt message should be printed to stderr.
diff --git a/lib/matplotlib/backends/backend_webagg.py b/lib/matplotlib/backends/backend_webagg.py
@@ -21,6 +21,7 @@
 import json
 import os
 import random
+import sys
 import socket
 import threading
 
@@ -333,11 +334,12 @@ def start(cls):
         launched. We may end up with two concurrently running loops in that
         unlucky case with all the expected consequences.
         """
-        print("Press Ctrl+C to stop server")
+        print("Press Ctrl+C to stop WebAgg server")
+        sys.stdout.flush()
         try:
             tornado.ioloop.IOLoop.instance().start()
         except KeyboardInterrupt:
-            print("Server stopped")
+            six.print_("Server is stopped", file=sys.stderr)
         finally:
             cls.started = False
 
