logging: clarified Filter documentation.

diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst
index 71d87cd56cb14905d28e322a41ff0d53347a0fae..4beeec654a62ede31bc18e28765da8019606fcf9 100644 (file)
--- a/Doc/library/logging.rst
+++ b/Doc/library/logging.rst
@@ -2708,6 +2708,9 @@ etc.) This means that events which have been generated by descendant loggers
 will not be filtered by a logger's filter setting, unless the filter has also
 been applied to those descendant loggers.
 
+You don't actually need to subclass ``Filter``: you can pass any instance
+which has a ``filter`` method with the same semantics.
+
 Other uses for filters
 ^^^^^^^^^^^^^^^^^^^^^^