merge with upstream 3.3 branchv3.3.1rc1

3 files changed, 42 insertions, 31 deletions

diff --git a/Doc/library/collections.abc.rst b/Doc/library/collections.abc.rst
index 558eb98..5eea0df 100644
--- a/Doc/library/collections.abc.rst
+++ b/Doc/library/collections.abc.rst
@@ -41,29 +41,35 @@ ABC                        Inherits from          Abstract Methods        Mixin
 :class:`Sized`                                    ``__len__``
 :class:`Callable`                                 ``__call__``
 
-:class:`Sequence`          :class:`Sized`,        ``__getitem__``         ``__contains__``, ``__iter__``, ``__reversed__``,
-                           :class:`Iterable`,                             ``index``, and ``count``
+:class:`Sequence`          :class:`Sized`,        ``__getitem__``,        ``__contains__``, ``__iter__``, ``__reversed__``,
+                           :class:`Iterable`,     ``__len__``             ``index``, and ``count``
                            :class:`Container`
 
-:class:`MutableSequence`   :class:`Sequence`      ``__setitem__``,        Inherited :class:`Sequence` methods and
-                                                  ``__delitem__``,        ``append``, ``reverse``, ``extend``, ``pop``,
-                                                  ``insert``              ``remove``, ``clear``, and ``__iadd__``
-
-:class:`Set`               :class:`Sized`,                                ``__le__``, ``__lt__``, ``__eq__``, ``__ne__``,
-                           :class:`Iterable`,                             ``__gt__``, ``__ge__``, ``__and__``, ``__or__``,
-                           :class:`Container`                             ``__sub__``, ``__xor__``, and ``isdisjoint``
-
-:class:`MutableSet`        :class:`Set`           ``add``,                Inherited :class:`Set` methods and
-                                                  ``discard``             ``clear``, ``pop``, ``remove``, ``__ior__``,
-                                                                          ``__iand__``, ``__ixor__``, and ``__isub__``
-
-:class:`Mapping`           :class:`Sized`,        ``__getitem__``         ``__contains__``, ``keys``, ``items``, ``values``,
-                           :class:`Iterable`,                             ``get``, ``__eq__``, and ``__ne__``
-                           :class:`Container`
-
-:class:`MutableMapping`    :class:`Mapping`       ``__setitem__``,        Inherited :class:`Mapping` methods and
-                                                  ``__delitem__``         ``pop``, ``popitem``, ``clear``, ``update``,
-                                                                          and ``setdefault``
+:class:`MutableSequence`   :class:`Sequence`      ``__getitem__``,        Inherited :class:`Sequence` methods and
+                                                  ``__setitem__``,        ``append``, ``reverse``, ``extend``, ``pop``,
+                                                  ``__delitem__``,        ``remove``, and ``__iadd__``
+                                                  ``__len__``,
+                                                  ``insert``
+
+:class:`Set`               :class:`Sized`,        ``__contains__``,       ``__le__``, ``__lt__``, ``__eq__``, ``__ne__``,
+                           :class:`Iterable`,     ``__iter__``,           ``__gt__``, ``__ge__``, ``__and__``, ``__or__``,
+                           :class:`Container`     ``__len__``             ``__sub__``, ``__xor__``, and ``isdisjoint``
+
+:class:`MutableSet`        :class:`Set`           ``__contains__``,       Inherited :class:`Set` methods and
+                                                  ``__iter__``,           ``clear``, ``pop``, ``remove``, ``__ior__``,
+                                                  ``__len__``,            ``__iand__``, ``__ixor__``, and ``__isub__``
+                                                  ``add``,
+                                                  ``discard``
+
+:class:`Mapping`           :class:`Sized`,        ``__getitem__``,        ``__contains__``, ``keys``, ``items``, ``values``,
+                           :class:`Iterable`,     ``__iter__``,           ``get``, ``__eq__``, and ``__ne__``
+                           :class:`Container`     ``__len__``
+
+:class:`MutableMapping`    :class:`Mapping`       ``__getitem__``,        Inherited :class:`Mapping` methods and
+                                                  ``__setitem__``,        ``pop``, ``popitem``, ``clear``, ``update``,
+                                                  ``__delitem__``,        and ``setdefault``
+                                                  ``__iter__``,
+                                                  ``__len__``
 
 
 :class:`MappingView`       :class:`Sized`                                 ``__len__``
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index 7e5f04f..60df11d 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -1627,6 +1627,8 @@ expression support in the :mod:`re` module).
    Return true if the string is a valid identifier according to the language
    definition, section :ref:`identifiers`.
 
+   Use :func:`keyword.iskeyword` to test for reserved identifiers such as
+   :keyword:`def` and :keyword:`class`.
 
 .. method:: str.islower()
 
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 92b21b5..a72ca44 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -356,7 +356,7 @@ are able to handle the less common cases not covered by the convenience
 functions.
 
 
-.. class:: Popen(args, bufsize=0, executable=None, stdin=None, stdout=None, \
+.. class:: Popen(args, bufsize=-1, executable=None, stdin=None, stdout=None, \
                  stderr=None, preexec_fn=None, close_fds=True, shell=False, \
                  cwd=None, env=None, universal_newlines=False, \
                  startupinfo=None, creationflags=0, restore_signals=True, \
@@ -428,17 +428,20 @@ functions.
       untrusted input.  See the warning under :ref:`frequently-used-arguments`
       for details.
 
-   *bufsize*, if given, has the same meaning as the corresponding argument to the
-   built-in open() function: :const:`0` means unbuffered, :const:`1` means line
-   buffered, any other positive value means use a buffer of (approximately) that
-   size.  A negative *bufsize* means to use the system default, which usually means
-   fully buffered.  The default value for *bufsize* is :const:`0` (unbuffered).
+   *bufsize* will be supplied as the corresponding argument to the :meth:`io.open`
+   function when creating the stdin/stdout/stderr pipe file objects:
+   :const:`0` means unbuffered (read and write are one system call and can return short),
+   :const:`1` means line buffered, any other positive value means use a buffer of
+   approximately that size.  A negative bufsize (the default) means
+   the system default of io.DEFAULT_BUFFER_SIZE will be used.
 
-   .. note::
+   .. versionchanged:: 3.2.4, 3.3.1
 
-      If you experience performance issues, it is recommended that you try to
-      enable buffering by setting *bufsize* to either -1 or a large enough
-      positive value (such as 4096).
+      *bufsize* now defaults to -1 to enable buffering by default to match the
+      behavior that most code expects.  In 3.2.0 through 3.2.3 and 3.3.0 it
+      incorrectly defaulted to :const:`0` which was unbuffered and allowed
+      short reads.  This was unintentional and did not match the behavior of
+      Python 2 as most code expected.
 
    The *executable* argument specifies a replacement program to execute.   It
    is very seldom needed.  When ``shell=False``, *executable* replaces the