Merge in all documentation changes since branching 3.4.0rc1.

1 files changed, 13 insertions, 5 deletions

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 4f19b37..8204dc3 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1226,6 +1226,10 @@ Basic customization
 
    The return value must be a string object.
 
+   .. versionchanged:: 3.4
+      The __format__ method of ``object`` itself raises a :exc:`TypeError`
+      if passed any non-empty string.
+
 
 .. _richcmpfuncs:
 .. method:: object.__lt__(self, other)
@@ -1643,6 +1647,8 @@ of these candidate metaclasses. If none of the candidate metaclasses meets
 that criterion, then the class definition will fail with ``TypeError``.
 
 
+.. _prepare:
+
 Preparing the class namespace
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -2044,11 +2050,13 @@ left undefined.
    ``&=``, ``^=``, ``|=``).  These methods should attempt to do the operation
    in-place (modifying *self*) and return the result (which could be, but does
    not have to be, *self*).  If a specific method is not defined, the augmented
-   assignment falls back to the normal methods.  For instance, to execute the
-   statement ``x += y``, where *x* is an instance of a class that has an
-   :meth:`__iadd__` method, ``x.__iadd__(y)`` is called.  If *x* is an instance
-   of a class that does not define a :meth:`__iadd__` method, ``x.__add__(y)``
-   and ``y.__radd__(x)`` are considered, as with the evaluation of ``x + y``.
+   assignment falls back to the normal methods.  For instance, if *x* is an
+   instance of a class with an :meth:`__iadd__` method, ``x += y`` is equivalent
+   to ``x = x.__iadd__(y)`` . Otherwise, ``x.__add__(y)`` and ``y.__radd__(x)``
+   are considered, as with the evaluation of ``x + y``. In certain situations,
+   augmented assignment can result in unexpected errors (see
+   :ref:`faq-augmented-assignment-tuple-error`), but this behavior is in
+   fact part of the data model.
 
 
 .. method:: object.__neg__(self)