Use pickle protocol 0 and use lambda for sorted key to avoid unicode problem for str.lower

examples/demo/multistroke/gesturedatabase.py

@@ -100,7 +100,7 @@ class GestureDatabase(GridLayout):
 
         self.selected_count = 0
         self.ids.gesture_list.clear_widgets()
-        for k in sorted(self.gdict, key=str.lower):
+        for k in sorted(self.gdict, key=lambda n: n.lower()):
             gitem = GestureDatabaseItem(name=k, gesture_list=self.gdict[k])
             gitem.bind(on_select=self.select_item)
             gitem.bind(on_deselect=self.deselect_item)

kivy/multistroke.py

@@ -390,7 +390,7 @@ class Recognizer(EventDispatcher):
         This method accepts optional :meth:`Recognizer.filter` arguments.
         '''
         io = BytesIO()
-        p = pickle.Pickler(io)
+        p = pickle.Pickler(io, protocol=0)
         multistrokes = []
         defaults = {'priority': 100, 'numpoints': 16, 'stroke_sens': True,
                     'orientation_sens': False, 'angle_similarity': 30.0}