--- rest25/library/pickle.rst	2008-12-19 16:58:08.000000000 +0900
+++ rest262/library/pickle.rst	2009-04-07 00:06:53.000000000 +0900
@@ -1,30 +1,27 @@
-
 :mod:`pickle` --- Python object serialization
 =============================================
 
 .. index::
    single: persistence
    pair: persistent; objects
    pair: serializing; objects
    pair: marshalling; objects
    pair: flattening; objects
    pair: pickling; objects
 
 .. module:: pickle
    :synopsis: Convert Python objects to streams of bytes and back.
-
-
-.. % Substantial improvements by Jim Kerr <jbkerr@sr.hp.com>.
-.. % Rewritten by Barry Warsaw <barry@zope.com>
+.. sectionauthor:: Jim Kerr <jbkerr@sr.hp.com>.
+.. sectionauthor:: Barry Warsaw <barry@zope.com>
 
 The :mod:`pickle` module implements a fundamental, but powerful algorithm for
 serializing and de-serializing a Python object structure.  "Pickling" is the
 process whereby a Python object hierarchy is converted into a byte stream, and
 "unpickling" is the inverse operation, whereby a byte stream is converted back
 into an object hierarchy.  Pickling (and unpickling) is alternatively known as
 "serialization", "marshalling," [#]_ or "flattening", however, to avoid
 confusion, the terms used here are "pickling" and "unpickling".
 
 This documentation describes both the :mod:`pickle` module and the
 :mod:`cPickle` module.
 
@@ -82,26 +79,26 @@
    The :mod:`pickle` module is not intended to be secure against erroneous or
    maliciously constructed data.  Never unpickle data received from an untrusted or
    unauthenticated source.
 
 Note that serialization is a more primitive notion than persistence; although
 :mod:`pickle` reads and writes file objects, it does not handle the issue of
 naming persistent objects, nor the (even more complicated) issue of concurrent
 access to persistent objects.  The :mod:`pickle` module can transform a complex
 object into a byte stream and it can transform the byte stream into an object
 with the same internal structure.  Perhaps the most obvious thing to do with
 these byte streams is to write them onto a file, but it is also conceivable to
 send them across a network or store them in a database.  The module
-:mod:`shelve` provides a simple interface to pickle and unpickle objects on DBM-
-style database files.
+:mod:`shelve` provides a simple interface to pickle and unpickle objects on
+DBM-style database files.
 
 
 Data stream format
 ------------------
 
 .. index::
    single: XDR
    single: External Data Representation
 
 The data format used by :mod:`pickle` is Python-specific.  This has the
 advantage that there are no restrictions imposed by external standards such as
 XDR (which can't represent pointer sharing); however it means that non-Python
@@ -113,27 +110,27 @@
 :mod:`pickle`'s representation) is that for debugging or recovery purposes it is
 possible for a human to read the pickled file with a standard text editor.
 
 There are currently 3 different protocols which can be used for pickling.
 
 * Protocol version 0 is the original ASCII protocol and is backwards compatible
   with earlier versions of Python.
 
 * Protocol version 1 is the old binary format which is also compatible with
   earlier versions of Python.
 
 * Protocol version 2 was introduced in Python 2.3.  It provides much more
-  efficient pickling of new-style classes.
+  efficient pickling of :term:`new-style class`\es.
 
-Refer to PEP 307 for more information.
+Refer to :pep:`307` for more information.
 
 If a *protocol* is not specified, protocol 0 is used. If *protocol* is specified
 as a negative value or :const:`HIGHEST_PROTOCOL`, the highest protocol version
 available will be used.
 
 .. versionchanged:: 2.3
    Introduced the *protocol* parameter.
 
 A binary format, which is slightly more efficient, can be chosen by specifying a
 *protocol* version >= 1.
 
 
@@ -240,104 +237,109 @@
    necessarily limited to) :exc:`AttributeError`, :exc:`EOFError`,
    :exc:`ImportError`, and :exc:`IndexError`.
 
 The :mod:`pickle` module also exports two callables [#]_, :class:`Pickler` and
 :class:`Unpickler`:
 
 
 .. class:: Pickler(file[, protocol])
 
    This takes a file-like object to which it will write a pickle data stream.
 
    If the *protocol* parameter is omitted, protocol 0 is used. If *protocol* is
-   specified as a negative value, the highest protocol version will be used.
+   specified as a negative value or :const:`HIGHEST_PROTOCOL`, the highest
+   protocol version will be used.
 
    .. versionchanged:: 2.3
       Introduced the *protocol* parameter.
 
    *file* must have a :meth:`write` method that accepts a single string argument.
    It can thus be an open file object, a :mod:`StringIO` object, or any other
    custom object that meets this interface.
 
-:class:`Pickler` objects define one (or two) public methods:
+   :class:`Pickler` objects define one (or two) public methods:
 
 
-.. method:: Pickler.dump(obj)
+   .. method:: dump(obj)
 
-   Write a pickled representation of *obj* to the open file object given in the
-   constructor.  Either the binary or ASCII format will be used, depending on the
-   value of the *protocol* argument passed to the constructor.
+      Write a pickled representation of *obj* to the open file object given in the
+      constructor.  Either the binary or ASCII format will be used, depending on the
+      value of the *protocol* argument passed to the constructor.
 
 
-.. method:: Pickler.clear_memo()
+   .. method:: clear_memo()
 
-   Clears the pickler's "memo".  The memo is the data structure that remembers
-   which objects the pickler has already seen, so that shared or recursive objects
-   pickled by reference and not by value.  This method is useful when re-using
-   picklers.
+      Clears the pickler's "memo".  The memo is the data structure that remembers
+      which objects the pickler has already seen, so that shared or recursive objects
+      pickled by reference and not by value.  This method is useful when re-using
+      picklers.
 
-   .. note::
+      .. note::
 
-      Prior to Python 2.3, :meth:`clear_memo` was only available on the picklers
-      created by :mod:`cPickle`.  In the :mod:`pickle` module, picklers have an
-      instance variable called :attr:`memo` which is a Python dictionary.  So to clear
-      the memo for a :mod:`pickle` module pickler, you could do the following::
+         Prior to Python 2.3, :meth:`clear_memo` was only available on the picklers
+         created by :mod:`cPickle`.  In the :mod:`pickle` module, picklers have an
+         instance variable called :attr:`memo` which is a Python dictionary.  So to clear
+         the memo for a :mod:`pickle` module pickler, you could do the following::
 
-         mypickler.memo.clear()
+            mypickler.memo.clear()
 
-      Code that does not need to support older versions of Python should simply use
-      :meth:`clear_memo`.
+         Code that does not need to support older versions of Python should simply use
+         :meth:`clear_memo`.
 
 It is possible to make multiple calls to the :meth:`dump` method of the same
 :class:`Pickler` instance.  These must then be matched to the same number of
 calls to the :meth:`load` method of the corresponding :class:`Unpickler`
 instance.  If the same object is pickled by multiple :meth:`dump` calls, the
 :meth:`load` will all yield references to the same object. [#]_
 
 :class:`Unpickler` objects are defined as:
 
 
 .. class:: Unpickler(file)
 
    This takes a file-like object from which it will read a pickle data stream.
    This class automatically determines whether the data stream was written in
    binary mode or not, so it does not need a flag as in the :class:`Pickler`
    factory.
 
    *file* must have two methods, a :meth:`read` method that takes an integer
    argument, and a :meth:`readline` method that requires no arguments.  Both
    methods should return a string.  Thus *file* can be a file object opened for
    reading, a :mod:`StringIO` object, or any other custom object that meets this
    interface.
 
-:class:`Unpickler` objects have one (or two) public methods:
+   :class:`Unpickler` objects have one (or two) public methods:
 
 
-.. method:: Unpickler.load()
+   .. method:: load()
 
-   Read a pickled object representation from the open file object given in the
-   constructor, and return the reconstituted object hierarchy specified therein.
+      Read a pickled object representation from the open file object given in
+      the constructor, and return the reconstituted object hierarchy specified
+      therein.
 
+      This method automatically determines whether the data stream was written
+      in binary mode or not.
 
-.. method:: Unpickler.noload()
 
-   This is just like :meth:`load` except that it doesn't actually create any
-   objects.  This is useful primarily for finding what's called "persistent ids"
-   that may be referenced in a pickle data stream.  See section
-   :ref:`pickle-protocol` below for more details.
+   .. method:: noload()
 
-   **Note:** the :meth:`noload` method is currently only available on
-   :class:`Unpickler` objects created with the :mod:`cPickle` module.
-   :mod:`pickle` module :class:`Unpickler`\ s do not have the :meth:`noload`
-   method.
+      This is just like :meth:`load` except that it doesn't actually create any
+      objects.  This is useful primarily for finding what's called "persistent
+      ids" that may be referenced in a pickle data stream.  See section
+      :ref:`pickle-protocol` below for more details.
+
+      **Note:** the :meth:`noload` method is currently only available on
+      :class:`Unpickler` objects created with the :mod:`cPickle` module.
+      :mod:`pickle` module :class:`Unpickler`\ s do not have the :meth:`noload`
+      method.
 
 
 What can be pickled and unpickled?
 ----------------------------------
 
 The following types can be pickled:
 
 * ``None``, ``True``, and ``False``
 
 * integers, long integers, floating point numbers, complex numbers
 
 * normal and Unicode strings
@@ -385,170 +387,188 @@
 purpose, so you can fix bugs in a class or add methods to the class and still
 load objects that were created with an earlier version of the class.  If you
 plan to have long-lived objects that will see many versions of a class, it may
 be worthwhile to put a version number in the objects so that suitable
 conversions can be made by the class's :meth:`__setstate__` method.
 
 
 .. _pickle-protocol:
 
 The pickle protocol
 -------------------
 
+.. currentmodule:: None
+
 This section describes the "pickling protocol" that defines the interface
 between the pickler/unpickler and the objects that are being serialized.  This
 protocol provides a standard way for you to define, customize, and control how
 your objects are serialized and de-serialized.  The description in this section
 doesn't cover specific customizations that you can employ to make the unpickling
 environment slightly safer from untrusted pickle data streams; see section
 :ref:`pickle-sub` for more details.
 
 
 .. _pickle-inst:
 
 Pickling and unpickling normal class instances
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-.. index::
-   single: __getinitargs__() (copy protocol)
-   single: __init__() (instance constructor)
-
-When a pickled class instance is unpickled, its :meth:`__init__` method is
-normally *not* invoked.  If it is desirable that the :meth:`__init__` method be
-called on unpickling, an old-style class can define a method
-:meth:`__getinitargs__`, which should return a *tuple* containing the arguments
-to be passed to the class constructor (:meth:`__init__` for example).  The
-:meth:`__getinitargs__` method is called at pickle time; the tuple it returns is
-incorporated in the pickle for the instance.
-
-.. index:: single: __getnewargs__() (copy protocol)
-
-New-style types can provide a :meth:`__getnewargs__` method that is used for
-protocol 2.  Implementing this method is needed if the type establishes some
-internal invariants when the instance is created, or if the memory allocation is
-affected by the values passed to the :meth:`__new__` method for the type (as it
-is for tuples and strings).  Instances of a new-style type :class:`C` are
-created using ::
+.. method:: object.__getinitargs__()
 
-   obj = C.__new__(C, \*args)
+   When a pickled class instance is unpickled, its :meth:`__init__` method is
+   normally *not* invoked.  If it is desirable that the :meth:`__init__` method
+   be called on unpickling, an old-style class can define a method
+   :meth:`__getinitargs__`, which should return a *tuple* containing the
+   arguments to be passed to the class constructor (:meth:`__init__` for
+   example).  The :meth:`__getinitargs__` method is called at pickle time; the
+   tuple it returns is incorporated in the pickle for the instance.
+
+.. method:: object.__getnewargs__()
+
+   New-style types can provide a :meth:`__getnewargs__` method that is used for
+   protocol 2.  Implementing this method is needed if the type establishes some
+   internal invariants when the instance is created, or if the memory allocation
+   is affected by the values passed to the :meth:`__new__` method for the type
+   (as it is for tuples and strings).  Instances of a :term:`new-style class`
+   ``C`` are created using ::
+
+      obj = C.__new__(C, *args)
+
+   where *args* is the result of calling :meth:`__getnewargs__` on the original
+   object; if there is no :meth:`__getnewargs__`, an empty tuple is assumed.
+
+.. method:: object.__getstate__()
+
+   Classes can further influence how their instances are pickled; if the class
+   defines the method :meth:`__getstate__`, it is called and the return state is
+   pickled as the contents for the instance, instead of the contents of the
+   instance's dictionary.  If there is no :meth:`__getstate__` method, the
+   instance's :attr:`__dict__` is pickled.
+
+.. method:: object.__setstate__()
+
+   Upon unpickling, if the class also defines the method :meth:`__setstate__`,
+   it is called with the unpickled state. [#]_ If there is no
+   :meth:`__setstate__` method, the pickled state must be a dictionary and its
+   items are assigned to the new instance's dictionary.  If a class defines both
+   :meth:`__getstate__` and :meth:`__setstate__`, the state object needn't be a
+   dictionary and these methods can do what they want. [#]_
 
+   .. warning::
 
-where *args* is the result of calling :meth:`__getnewargs__` on the original
-object; if there is no :meth:`__getnewargs__`, an empty tuple is assumed.
+      For :term:`new-style class`\es, if :meth:`__getstate__` returns a false
+      value, the :meth:`__setstate__` method will not be called.
 
-.. index::
-   single: __getstate__() (copy protocol)
-   single: __setstate__() (copy protocol)
-   single: __dict__ (instance attribute)
-
-Classes can further influence how their instances are pickled; if the class
-defines the method :meth:`__getstate__`, it is called and the return state is
-pickled as the contents for the instance, instead of the contents of the
-instance's dictionary.  If there is no :meth:`__getstate__` method, the
-instance's :attr:`__dict__` is pickled.
-
-Upon unpickling, if the class also defines the method :meth:`__setstate__`, it
-is called with the unpickled state. [#]_  If there is no :meth:`__setstate__`
-method, the pickled state must be a dictionary and its items are assigned to the
-new instance's dictionary.  If a class defines both :meth:`__getstate__` and
-:meth:`__setstate__`, the state object needn't be a dictionary and these methods
-can do what they want. [#]_
-
-.. warning::
+.. note::
 
-   For new-style classes, if :meth:`__getstate__` returns a false value, the
-   :meth:`__setstate__` method will not be called.
+   At unpickling time, some methods like :meth:`__getattr__`,
+   :meth:`__getattribute__`, or :meth:`__setattr__` may be called upon the
+   instance.  In case those methods rely on some internal invariant being
+   true, the type should implement either :meth:`__getinitargs__` or
+   :meth:`__getnewargs__` to establish such an invariant; otherwise, neither
+   :meth:`__new__` nor :meth:`__init__` will be called.
 
 
 Pickling and unpickling extension types
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-When the :class:`Pickler` encounters an object of a type it knows nothing about
---- such as an extension type --- it looks in two places for a hint of how to
-pickle it.  One alternative is for the object to implement a :meth:`__reduce__`
-method.  If provided, at pickling time :meth:`__reduce__` will be called with no
-arguments, and it must return either a string or a tuple.
-
-If a string is returned, it names a global variable whose contents are pickled
-as normal.  The string returned by :meth:`__reduce__` should be the object's
-local name relative to its module; the pickle module searches the module
-namespace to determine the object's module.
-
-When a tuple is returned, it must be between two and five elements long.
-Optional elements can either be omitted, or ``None`` can be provided  as their
-value.  The semantics of each element are:
-
-* A callable object that will be called to create the initial version of the
-  object.  The next element of the tuple will provide arguments for this callable,
-  and later elements provide additional state information that will subsequently
-  be used to fully reconstruct the pickled date.
-
-  In the unpickling environment this object must be either a class, a callable
-  registered as a "safe constructor" (see below), or it must have an attribute
-  :attr:`__safe_for_unpickling__` with a true value. Otherwise, an
-  :exc:`UnpicklingError` will be raised in the unpickling environment.  Note that
-  as usual, the callable itself is pickled by name.
-
-* A tuple of arguments for the callable object.
-
-  .. versionchanged:: 2.5
-     Formerly, this argument could also be ``None``.
-
-* Optionally, the object's state, which will be passed to the object's
-  :meth:`__setstate__` method as described in section :ref:`pickle-inst`.  If the
-  object has no :meth:`__setstate__` method, then, as above, the value must be a
-  dictionary and it will be added to the object's :attr:`__dict__`.
-
-* Optionally, an iterator (and not a sequence) yielding successive list items.
-  These list items will be pickled, and appended to the object using either
-  ``obj.append(item)`` or ``obj.extend(list_of_items)``.  This is primarily used
-  for list subclasses, but may be used by other classes as long as they have
-  :meth:`append` and :meth:`extend` methods with the appropriate signature.
-  (Whether :meth:`append` or :meth:`extend` is used depends on which pickle
-  protocol version is used as well as the number of items to append, so both must
-  be supported.)
-
-* Optionally, an iterator (not a sequence) yielding successive dictionary items,
-  which should be tuples of the form ``(key, value)``.  These items will be
-  pickled and stored to the object using ``obj[key] = value``. This is primarily
-  used for dictionary subclasses, but may be used by other classes as long as they
-  implement :meth:`__setitem__`.
-
-It is sometimes useful to know the protocol version when implementing
-:meth:`__reduce__`.  This can be done by implementing a method named
-:meth:`__reduce_ex__` instead of :meth:`__reduce__`. :meth:`__reduce_ex__`, when
-it exists, is called in preference over :meth:`__reduce__` (you may still
-provide :meth:`__reduce__` for backwards compatibility).  The
-:meth:`__reduce_ex__` method will be called with a single integer argument, the
-protocol version.
-
-The :class:`object` class implements both :meth:`__reduce__` and
-:meth:`__reduce_ex__`; however, if a subclass overrides :meth:`__reduce__` but
-not :meth:`__reduce_ex__`, the :meth:`__reduce_ex__` implementation detects this
-and calls :meth:`__reduce__`.
+.. method:: object.__reduce__()
+
+   When the :class:`Pickler` encounters an object of a type it knows nothing
+   about --- such as an extension type --- it looks in two places for a hint of
+   how to pickle it.  One alternative is for the object to implement a
+   :meth:`__reduce__` method.  If provided, at pickling time :meth:`__reduce__`
+   will be called with no arguments, and it must return either a string or a
+   tuple.
+
+   If a string is returned, it names a global variable whose contents are
+   pickled as normal.  The string returned by :meth:`__reduce__` should be the
+   object's local name relative to its module; the pickle module searches the
+   module namespace to determine the object's module.
+
+   When a tuple is returned, it must be between two and five elements long.
+   Optional elements can either be omitted, or ``None`` can be provided as their
+   value.  The contents of this tuple are pickled as normal and used to
+   reconstruct the object at unpickling time.  The semantics of each element
+   are:
+
+   * A callable object that will be called to create the initial version of the
+     object.  The next element of the tuple will provide arguments for this
+     callable, and later elements provide additional state information that will
+     subsequently be used to fully reconstruct the pickled data.
+
+     In the unpickling environment this object must be either a class, a
+     callable registered as a "safe constructor" (see below), or it must have an
+     attribute :attr:`__safe_for_unpickling__` with a true value. Otherwise, an
+     :exc:`UnpicklingError` will be raised in the unpickling environment.  Note
+     that as usual, the callable itself is pickled by name.
+
+   * A tuple of arguments for the callable object.
+
+     .. versionchanged:: 2.5
+        Formerly, this argument could also be ``None``.
+
+   * Optionally, the object's state, which will be passed to the object's
+     :meth:`__setstate__` method as described in section :ref:`pickle-inst`.  If
+     the object has no :meth:`__setstate__` method, then, as above, the value
+     must be a dictionary and it will be added to the object's :attr:`__dict__`.
+
+   * Optionally, an iterator (and not a sequence) yielding successive list
+     items.  These list items will be pickled, and appended to the object using
+     either ``obj.append(item)`` or ``obj.extend(list_of_items)``.  This is
+     primarily used for list subclasses, but may be used by other classes as
+     long as they have :meth:`append` and :meth:`extend` methods with the
+     appropriate signature.  (Whether :meth:`append` or :meth:`extend` is used
+     depends on which pickle protocol version is used as well as the number of
+     items to append, so both must be supported.)
+
+   * Optionally, an iterator (not a sequence) yielding successive dictionary
+     items, which should be tuples of the form ``(key, value)``.  These items
+     will be pickled and stored to the object using ``obj[key] = value``. This
+     is primarily used for dictionary subclasses, but may be used by other
+     classes as long as they implement :meth:`__setitem__`.
+
+.. method:: object.__reduce_ex__(protocol)
+
+   It is sometimes useful to know the protocol version when implementing
+   :meth:`__reduce__`.  This can be done by implementing a method named
+   :meth:`__reduce_ex__` instead of :meth:`__reduce__`. :meth:`__reduce_ex__`,
+   when it exists, is called in preference over :meth:`__reduce__` (you may
+   still provide :meth:`__reduce__` for backwards compatibility).  The
+   :meth:`__reduce_ex__` method will be called with a single integer argument,
+   the protocol version.
+
+   The :class:`object` class implements both :meth:`__reduce__` and
+   :meth:`__reduce_ex__`; however, if a subclass overrides :meth:`__reduce__`
+   but not :meth:`__reduce_ex__`, the :meth:`__reduce_ex__` implementation
+   detects this and calls :meth:`__reduce__`.
 
 An alternative to implementing a :meth:`__reduce__` method on the object to be
 pickled, is to register the callable with the :mod:`copy_reg` module.  This
 module provides a way for programs to register "reduction functions" and
 constructors for user-defined types.   Reduction functions have the same
 semantics and interface as the :meth:`__reduce__` method described above, except
 that they are called with a single argument, the object to be pickled.
 
 The registered constructor is deemed a "safe constructor" for purposes of
 unpickling as described above.
 
 
 Pickling and unpickling external objects
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+.. index::
+   single: persistent_id (pickle protocol)
+   single: persistent_load (pickle protocol)
+
 For the benefit of object persistence, the :mod:`pickle` module supports the
 notion of a reference to an object outside the pickled data stream.  Such
 objects are referenced by a "persistent id", which is just an arbitrary string
 of printable ASCII characters. The resolution of such names is not defined by
 the :mod:`pickle` module; it will delegate this resolution to user defined
 functions on the pickler and unpickler. [#]_
 
 To define external persistent id resolution, you need to set the
 :attr:`persistent_id` attribute of the pickler object and the
 :attr:`persistent_load` attribute of the unpickler object.
 
 To pickle objects that have an external persistent id, the pickler must have a
@@ -609,35 +629,39 @@
 
    j = up.load()
    print j
 
 In the :mod:`cPickle` module, the unpickler's :attr:`persistent_load` attribute
 can also be set to a Python list, in which case, when the unpickler reaches a
 persistent id, the persistent id string will simply be appended to this list.
 This functionality exists so that a pickle data stream can be "sniffed" for
 object references without actually instantiating all the objects in a pickle.
 [#]_  Setting :attr:`persistent_load` to a list is usually used in conjunction
 with the :meth:`noload` method on the Unpickler.
 
-.. % BAW: Both pickle and cPickle support something called
-.. % inst_persistent_id() which appears to give unknown types a second
-.. % shot at producing a persistent id.  Since Jim Fulton can't remember
-.. % why it was added or what it's for, I'm leaving it undocumented.
+.. BAW: Both pickle and cPickle support something called inst_persistent_id()
+   which appears to give unknown types a second shot at producing a persistent
+   id.  Since Jim Fulton can't remember why it was added or what it's for, I'm
+   leaving it undocumented.
 
 
 .. _pickle-sub:
 
 Subclassing Unpicklers
 ----------------------
 
+.. index::
+   single: load_global() (pickle protocol)
+   single: find_global() (pickle protocol)
+
 By default, unpickling will import any class that it finds in the pickle data.
 You can control exactly what gets unpickled and what gets called by customizing
 your unpickler.  Unfortunately, exactly how you do this is different depending
 on whether you're using :mod:`pickle` or :mod:`cPickle`. [#]_
 
 In the :mod:`pickle` module, you need to derive a subclass from
 :class:`Unpickler`, overriding the :meth:`load_global` method.
 :meth:`load_global` should read two lines from the pickle data stream where the
 first line will the name of the module containing the class and the second line
 will be the name of the instance's class.  It then looks up the class, possibly
 importing the module and digging out the attribute, then it appends what it
 finds to the unpickler's stack.  Later on, this class will be assigned to the
@@ -680,98 +704,101 @@
    selfref_list.append(selfref_list)
 
    output = open('data.pkl', 'wb')
 
    # Pickle dictionary using protocol 0.
    pickle.dump(data1, output)
 
    # Pickle the list using the highest protocol available.
    pickle.dump(selfref_list, output, -1)
 
    output.close()
 
-The following example reads the resulting pickled data.  When reading a pickle-
-containing file, you should open the file in binary mode because you can't be
-sure if the ASCII or binary format was used. ::
+The following example reads the resulting pickled data.  When reading a
+pickle-containing file, you should open the file in binary mode because you
+can't be sure if the ASCII or binary format was used. ::
 
    import pprint, pickle
 
    pkl_file = open('data.pkl', 'rb')
 
    data1 = pickle.load(pkl_file)
    pprint.pprint(data1)
 
    data2 = pickle.load(pkl_file)
    pprint.pprint(data2)
 
    pkl_file.close()
 
 Here's a larger example that shows how to modify pickling behavior for a class.
 The :class:`TextReader` class opens a text file, and returns the line number and
 line contents each time its :meth:`readline` method is called. If a
 :class:`TextReader` instance is pickled, all attributes *except* the file object
 member are saved. When the instance is unpickled, the file is reopened, and
 reading resumes from the last location. The :meth:`__setstate__` and
 :meth:`__getstate__` methods are used to implement this behavior. ::
 
+   #!/usr/local/bin/python
+
    class TextReader:
        """Print and number lines in a text file."""
        def __init__(self, file):
            self.file = file
            self.fh = open(file)
            self.lineno = 0
 
        def readline(self):
            self.lineno = self.lineno + 1
            line = self.fh.readline()
            if not line:
                return None
            if line.endswith("\n"):
                line = line[:-1]
            return "%d: %s" % (self.lineno, line)
 
        def __getstate__(self):
            odict = self.__dict__.copy() # copy the dict since we change it
            del odict['fh']              # remove filehandle entry
            return odict
 
-       def __setstate__(self,dict):
+       def __setstate__(self, dict):
            fh = open(dict['file'])      # reopen file
            count = dict['lineno']       # read from file...
            while count:                 # until line count is restored
                fh.readline()
                count = count - 1
            self.__dict__.update(dict)   # update attributes
            self.fh = fh                 # save the file object
 
 A sample usage might be something like this::
 
    >>> import TextReader
    >>> obj = TextReader.TextReader("TextReader.py")
    >>> obj.readline()
    '1: #!/usr/local/bin/python'
-   >>> # (more invocations of obj.readline() here)
-   ... obj.readline()
-   '7: class TextReader:'
+   >>> obj.readline()
+   '2: '
+   >>> obj.readline()
+   '3: class TextReader:'
    >>> import pickle
-   >>> pickle.dump(obj,open('save.p','w'))
+   >>> pickle.dump(obj, open('save.p', 'wb'))
 
 If you want to see that :mod:`pickle` works across Python processes, start
 another Python session, before continuing.  What follows can happen from either
 the same process or a new process. ::
 
    >>> import pickle
-   >>> reader = pickle.load(open('save.p'))
+   >>> reader = pickle.load(open('save.p', 'rb'))
    >>> reader.readline()
-   '8:     "Print and number lines in a text file."'
+   '4:     """Print and number lines in a text file."""'
 
 
 .. seealso::
 
    Module :mod:`copy_reg`
       Pickle interface constructor registration for extension types.
 
    Module :mod:`shelve`
       Indexed databases of objects; uses :mod:`pickle`.
 
    Module :mod:`copy`
       Shallow and deep object copying.
