--- a/src/pyams_utils/session.py	Wed Nov 20 19:26:23 2019 +0100
+++ b/src/pyams_utils/session.py	Fri Nov 22 18:51:37 2019 +0100
@@ -18,9 +18,9 @@
 It also adds to function to get and set session data.
 """
 
-__docformat__ = 'restructuredtext'
+from pyams_utils.request import check_request
 
-from pyams_utils.request import check_request
+__docformat__ = 'restructuredtext'
 
 
 def get_session_data(request, app, key, default=None):
@@ -66,7 +66,7 @@
     session['{0}::{1}'.format(app, key)] = value
 
 
-_marker = object()
+_MARKER = object()
 
 
 def session_property(app, key=None, prefix=None):
@@ -89,8 +89,8 @@
                 key = key(obj, *args, **kwargs)
             if not key:
                 key = '{1}::{0!r}'.format(obj, prefix or func.__name__)
-            data = get_session_data(request, app, key, _marker)
-            if data is _marker:
+            data = get_session_data(request, app, key, _MARKER)
+            if data is _MARKER:
                 data = func
                 if callable(data):
                     data = data(obj, *args, **kwargs)