Add advice on choosing between DictMixin and MutableMapping

diff --git a/Doc/library/userdict.rst b/Doc/library/userdict.rst
index 11d46ed109df0c0e0972a3f4ebf1dc643bf0c49d..a97732d03cc797b9fe40b2fe4b54e55e060e7262 100644 (file)
--- a/Doc/library/userdict.rst
+++ b/Doc/library/userdict.rst
@@ -68,6 +68,8 @@ provide the following attribute:
    Since the mixin has no knowledge of the subclass constructor, it does not define
    :meth:`__init__` or :meth:`copy`.
 
+   Starting with Python version 2.6, it is recommended to use
+   :class:`collections.MutableMapping` instead of :class:`DictMixin`.
 
 :mod:`UserList` --- Class wrapper for list objects
 ==================================================