Issue #26557: Note that mapping view methods are not present in UserDict or shelves.

diff --git a/Doc/library/shelve.rst b/Doc/library/shelve.rst
index 8c65790ed7c24067bf9c6fc8fbe759f70e78b0cc..4058c3407f69c4eed1e62c928acaeca607c747d7 100644 (file)
--- a/Doc/library/shelve.rst
+++ b/Doc/library/shelve.rst
@@ -53,8 +53,12 @@ lots of shared  sub-objects.  The keys are ordinary strings.
    to load a shelf from an untrusted source.  Like with pickle, loading a shelf
    can execute arbitrary code.
 
-Shelf objects support all methods supported by dictionaries.  This eases the
-transition from dictionary based scripts to those requiring persistent storage.
+Shelf objects support most of the methods supported by dictionaries.  This
+eases the transition from dictionary based scripts to those requiring
+persistent storage.
+
+Note, the Python 3 transition methods (:meth:`~dict.viewkeys`,
+:meth:`~dict.viewvalues`, and :meth:`~dict.viewitems`) are not supported.
 
 Two additional methods are supported:
 

diff --git a/Doc/library/userdict.rst b/Doc/library/userdict.rst
index 0585bda4a54f5aa5fc93826da9ea8ef2ec07681f..2363a8ef2f92032ae0e3a147c6706571e988bc6d 100644 (file)
--- a/Doc/library/userdict.rst
+++ b/Doc/library/userdict.rst
@@ -74,6 +74,9 @@ provide the following attribute:
    Starting with Python version 2.6, it is recommended to use
    :class:`collections.MutableMapping` instead of :class:`DictMixin`.
 
+   Note that DictMixin does not implement the :meth:`~dict.viewkeys`,
+   :meth:`~dict.viewvalues`, or :meth:`~dict.viewitems` methods.
+
 :mod:`UserList` --- Class wrapper for list objects
 ==================================================