Implement PEP 380 - 'yield from' (closes #11682)
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
index cb429c8..5ba66cb 100644
--- a/Doc/library/dis.rst
+++ b/Doc/library/dis.rst
@@ -431,6 +431,13 @@
    Pops ``TOS`` and yields it from a :term:`generator`.
 
 
+.. opcode:: YIELD_FROM
+
+   Pops ``TOS`` and delegates to it as a subiterator from a :term:`generator`.
+
+   .. versionadded:: 3.3
+
+
 .. opcode:: IMPORT_STAR
 
    Loads all symbols not starting with ``'_'`` directly from the module TOS to the
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
index 49cec1e..a9a16d3 100644
--- a/Doc/library/exceptions.rst
+++ b/Doc/library/exceptions.rst
@@ -250,7 +250,16 @@
 .. exception:: StopIteration
 
    Raised by built-in function :func:`next` and an :term:`iterator`\'s
-   :meth:`__next__` method to signal that there are no further values.
+   :meth:`__next__` method to signal that there are no further items to be
+   produced by the iterator.
+
+   The exception object has a single attribute :attr:`value`, which is
+   given as an argument when constructing the exception, and defaults
+   to :const:`None`.
+
+   When a generator function returns, a new :exc:`StopIteration` instance is
+   raised, and the value returned by the function is used as the
+   :attr:`value` parameter to the constructor of the exception.
 
 
 .. exception:: SyntaxError