[2.7] Move __missing__ after __delitem__ in Data model. (GH-10923). (GH-10944)

(cherry picked from commit 1ce853f3)
Co-authored-by: Andre Delfino <adelfino@gmail.com>

Doc/reference/datamodel.rst

@@ -1919,12 +1919,6 @@ sequences, it should iterate through the values.
       indexes to allow proper detection of the end of the sequence.
 
 
-.. method:: object.__missing__(self, key)
-
-   Called by :class:`dict`\ .\ :meth:`__getitem__` to implement ``self[key]`` for dict subclasses
-   when key is not in the dictionary.
-
-
 .. method:: object.__setitem__(self, key, value)
 
    Called to implement assignment to ``self[key]``.  Same note as for
@@ -1943,6 +1937,12 @@ sequences, it should iterate through the values.
    values as for the :meth:`__getitem__` method.
 
 
+.. method:: object.__missing__(self, key)
+
+   Called by :class:`dict`\ .\ :meth:`__getitem__` to implement ``self[key]`` for dict subclasses
+   when key is not in the dictionary.
+
+
 .. method:: object.__iter__(self)
 
    This method is called when an iterator is required for a container. This method