path: root/testing/web-platform/tests/tools/six/documentation/index.rst

Six: Python 2 and 3 Compatibility Library
=========================================

.. module:: six
   :synopsis: Python 2 and 3 compatibility

.. moduleauthor:: Benjamin Peterson <benjamin@python.org>
.. sectionauthor:: Benjamin Peterson <benjamin@python.org>


Six provides simple utilities for wrapping over differences between Python 2 and
Python 3.  It is intended to support codebases that work on both Python 2 and 3
without modification.  six consists of only one Python file, so it is painless
to copy into a project.

Six can be downloaded on `PyPi <http://pypi.python.org/pypi/six/>`_.  Its bug
tracker and code hosting is on `BitBucket <http://bitbucket.org/gutworth/six>`_.

The name, "six", comes from the fact that 2*3 equals 6.  Why not addition?
Multiplication is more powerful, and, anyway, "five" has already been snatched
away by the Zope Five project.


Indices and tables
------------------

* :ref:`genindex`
* :ref:`search`


Package contents
----------------

.. data:: PY2

   A boolean indicating if the code is running on Python 2.

.. data:: PY3

   A boolean indicating if the code is running on Python 3.


Constants
>>>>>>>>>

Six provides constants that may differ between Python versions.  Ones ending
``_types`` are mostly useful as the second argument to ``isinstance`` or
``issubclass``.


.. data:: class_types

   Possible class types.  In Python 2, this encompasses old-style and new-style
   classes.  In Python 3, this is just new-styles.


.. data:: integer_types

   Possible integer types.  In Python 2, this is :func:`py2:long` and
   :func:`py2:int`, and in Python 3, just :func:`py3:int`.


.. data:: string_types

   Possible types for text data.  This is :func:`py2:basestring` in Python 2 and
   :func:`py3:str` in Python 3.


.. data:: text_type

   Type for representing (Unicode) textual data.  This is :func:`py2:unicode` in
   Python 2 and :func:`py3:str` in Python 3.


.. data:: binary_type

   Type for representing binary data.  This is :func:`py2:str` in Python 2 and
   :func:`py3:bytes` in Python 3.


.. data:: MAXSIZE

   The maximum  size of a  container like :func:`py3:list`  or :func:`py3:dict`.
   This  is  equivalent  to  :data:`py3:sys.maxsize` in  Python  2.6  and  later
   (including 3.x).   Note, this is temptingly  similar to, but not  the same as
   :data:`py2:sys.maxint`  in  Python  2.   There is  no  direct  equivalent  to
   :data:`py2:sys.maxint` in  Python 3  because its integer  type has  no limits
   aside from memory.


Here's example usage of the module::

   import six

   def dispatch_types(value):
       if isinstance(value, six.integer_types):
           handle_integer(value)
       elif isinstance(value, six.class_types):
           handle_class(value)
       elif isinstance(value, six.string_types):
           handle_string(value)


Object model compatibility
>>>>>>>>>>>>>>>>>>>>>>>>>>

Python 3 renamed the attributes of several intepreter data structures.  The
following accessors are available.  Note that the recommended way to inspect
functions and methods is the stdlib :mod:`py3:inspect` module.


.. function:: get_unbound_function(meth)

   Get the function out of unbound method *meth*.  In Python 3, unbound methods
   don't exist, so this function just returns *meth* unchanged.  Example
   usage::

      from six import get_unbound_function

      class X(object):
          def method(self):
              pass
      method_function = get_unbound_function(X.method)


.. function:: get_method_function(meth)

   Get the function out of method object *meth*.


.. function:: get_method_self(meth)

   Get the ``self`` of bound method *meth*.


.. function:: get_function_closure(func)

   Get the closure (list of cells) associated with *func*.  This is equivalent
   to ``func.__closure__`` on Python 2.6+ and ``func.func_closure`` on Python
   2.5.


.. function:: get_function_code(func)

   Get the code object associated with *func*.  This is equivalent to
   ``func.__code__`` on Python 2.6+ and ``func.func_code`` on Python 2.5.


.. function:: get_function_defaults(func)

   Get the defaults tuple associated with *func*.  This is equivalent to
   ``func.__defaults__`` on Python 2.6+ and ``func.func_defaults`` on Python
   2.5.


.. function:: get_function_globals(func)

   Get the globals of *func*.  This is equivalent to ``func.__globals__`` on
   Python 2.6+ and ``func.func_globals`` on Python 2.5.


.. function:: next(it)
              advance_iterator(it)

   Get the next item of iterator *it*.  :exc:`py3:StopIteration` is raised if
   the iterator is exhausted.  This is a replacement for calling ``it.next()``
   in Python 2 and ``next(it)`` in Python 3.


.. function:: callable(obj)

   Check if *obj* can be called.  Note ``callable`` has returned in Python 3.2,
   so using six's version is only necessary when supporting Python 3.0 or 3.1.


.. function:: iterkeys(dictionary, **kwargs)

   Returns an iterator over *dictionary*\'s keys. This replaces
   ``dictionary.iterkeys()`` on Python 2 and ``dictionary.keys()`` on
   Python 3.  *kwargs* are passed through to the underlying method.


.. function:: itervalues(dictionary, **kwargs)

   Returns an iterator over *dictionary*\'s values. This replaces
   ``dictionary.itervalues()`` on Python 2 and ``dictionary.values()`` on
   Python 3.  *kwargs* are passed through to the underlying method.


.. function:: iteritems(dictionary, **kwargs)

   Returns an iterator over *dictionary*\'s items. This replaces
   ``dictionary.iteritems()`` on Python 2 and ``dictionary.items()`` on
   Python 3.  *kwargs* are passed through to the underlying method.


.. function:: iterlists(dictionary, **kwargs)

   Calls ``dictionary.iterlists()`` on Python 2 and ``dictionary.lists()`` on
   Python 3.  No builtin Python mapping type has such a method; this method is
   intended for use with multi-valued dictionaries like `Werkzeug's
   <http://werkzeug.pocoo.org/docs/datastructures/#werkzeug.datastructures.MultiDict>`_.
   *kwargs* are passed through to the underlying method.


.. function:: viewkeys(dictionary)

   Return a view over *dictionary*\'s keys. This replaces
   :meth:`py2:dict.viewkeys` on Python 2.7 and :meth:`py3:dict.keys` on
   Python 3.


.. function:: viewvalues(dictionary)

   Return a view over *dictionary*\'s values. This replaces
   :meth:`py2:dict.viewvalues` on Python 2.7 and :meth:`py3:dict.values` on
   Python 3.


.. function:: viewitems(dictionary)

   Return a view over *dictionary*\'s items. This replaces
   :meth:`py2:dict.viewitems` on Python 2.7 and :meth:`py3:dict.items` on
   Python 3.


.. function:: create_bound_method(func, obj)

   Return a method object wrapping *func* and bound to *obj*.  On both Python 2
   and 3, this will return a :func:`py3:types.MethodType` object.  The reason
   this wrapper exists is that on Python 2, the ``MethodType`` constructor
   requires the *obj*'s class to be passed.


.. class:: Iterator

   A class for making portable iterators. The intention is that it be subclassed
   and subclasses provide a ``__next__`` method. In Python 2, :class:`Iterator`
   has one method: ``next``. It simply delegates to ``__next__``. An alternate
   way to do this would be to simply alias ``next`` to ``__next__``. However,
   this interacts badly with subclasses that override
   ``__next__``. :class:`Iterator` is empty on Python 3. (In fact, it is just
   aliased to :class:`py3:object`.)


.. function:: wraps(wrapped, assigned=functools.WRAPPER_ASSIGNMENTS, updated=functools.WRAPPER_UPDATES)

   This is exactly the :func:`py3:functools.wraps` decorator, but it sets the
   ``__wrapped__`` attribute on what it decorates as :func:`py3:functools.wraps`
   does on Python versions after 3.2.


Syntax compatibility
>>>>>>>>>>>>>>>>>>>>

These functions smooth over operations which have different syntaxes between
Python 2 and 3.


.. function:: exec_(code, globals=None, locals=None)

   Execute *code* in the scope of *globals* and *locals*.  *code* can be a
   string or a code object.  If *globals* or *locals* are not given, they will
   default to the scope of the caller.  If just *globals* is given, it will also
   be used as *locals*.

   .. note::

      Python 3's :func:`py3:exec` doesn't take keyword arguments, so calling
      :func:`exec` with them should be avoided.


.. function:: print_(*args, *, file=sys.stdout, end="\\n", sep=" ")

   Print *args* into *file*.  Each argument will be separated with *sep* and
   *end* will be written to the file after the last argument is printed.

   .. note::

      In Python 2, this function imitates Python 3's :func:`py3:print` by not
      having softspace support.  If you don't know what that is, you're probably
      ok. :)


.. function:: raise_from(exc_value, exc_value_from)

   Raise an exception from a context.  On Python 3, this is equivalent to
   ``raise exc_value from exc_value_from``.  On Python 2, which does not support
   exception chaining, it is equivalent to ``raise exc_value``.


.. function:: reraise(exc_type, exc_value, exc_traceback=None)

   Reraise an exception, possibly with a different traceback.  In the simple
   case, ``reraise(*sys.exc_info())`` with an active exception (in an except
   block) reraises the current exception with the last traceback.  A different
   traceback can be specified with the *exc_traceback* parameter.  Note that
   since the exception reraising is done within the :func:`reraise` function,
   Python will attach the call frame of :func:`reraise` to whatever traceback is
   raised.


.. function:: with_metaclass(metaclass, *bases)

   Create a new class with base classes *bases* and metaclass *metaclass*.  This
   is designed to be used in class declarations like this: ::

      from six import with_metaclass

      class Meta(type):
          pass

      class Base(object):
          pass

      class MyClass(with_metaclass(Meta, Base)):
          pass

   Another way to set a metaclass on a class is with the :func:`add_metaclass`
   decorator.


.. function:: add_metaclass(metaclass)

   Class decorator that replaces a normally-constructed class with a
   metaclass-constructed one.  Example usage: ::

       @add_metaclass(Meta)
       class MyClass(object):
           pass

   That code produces a class equivalent to ::

       class MyClass(object, metaclass=Meta):
           pass

   on Python 3 or ::

       class MyClass(object):
           __metaclass__ = MyMeta

   on Python 2.

   Note that class decorators require Python 2.6. However, the effect of the
   decorator can be emulated on Python 2.5 like so::

       class MyClass(object):
           pass
       MyClass = add_metaclass(Meta)(MyClass)


Binary and text data
>>>>>>>>>>>>>>>>>>>>

Python 3 enforces the distinction between byte strings and text strings far more
rigoriously than Python 2 does; binary data cannot be automatically coerced to
or from text data.  six provides several functions to assist in classifying
string data in all Python versions.


.. function:: b(data)

   A "fake" bytes literal.  *data* should always be a normal string literal.  In
   Python 2, :func:`b` returns a 8-bit string.  In Python 3, *data* is encoded
   with the latin-1 encoding to bytes.


   .. note::

      Since all Python versions 2.6 and after support the ``b`` prefix,
      :func:`b`, code without 2.5 support doesn't need :func:`b`.


.. function:: u(text)

   A "fake" unicode literal.  *text* should always be a normal string literal.
   In Python 2, :func:`u` returns unicode, and in Python 3, a string.  Also, in
   Python 2, the string is decoded with the ``unicode-escape`` codec, which
   allows unicode escapes to be used in it.


   .. note::

      In Python 3.3, the ``u`` prefix has been reintroduced. Code that only
      supports Python 3 versions greater than 3.3 thus does not need
      :func:`u`.

   .. note::

      On Python 2, :func:`u` doesn't know what the encoding of the literal
      is. Each byte is converted directly to the unicode codepoint of the same
      value. Because of this, it's only safe to use :func:`u` with strings of
      ASCII data.


.. function:: unichr(c)

   Return the (Unicode) string representing the codepoint *c*.  This is
   equivalent to :func:`py2:unichr` on Python 2 and :func:`py3:chr` on Python 3.


.. function:: int2byte(i)

   Converts *i* to a byte.  *i* must be in ``range(0, 256)``.  This is
   equivalent to :func:`py2:chr` in Python 2 and ``bytes((i,))`` in Python 3.


.. function:: byte2int(bs)

   Converts the first byte of *bs* to an integer.  This is equivalent to
   ``ord(bs[0])`` on Python 2 and ``bs[0]`` on Python 3.


.. function:: indexbytes(buf, i)

   Return the byte at index *i* of *buf* as an integer.  This is equivalent to
   indexing a bytes object in Python 3.


.. function:: iterbytes(buf)

   Return an iterator over bytes in *buf* as integers.  This is equivalent to
   a bytes object iterator in Python 3.


.. data:: StringIO

   This is an fake file object for textual data.  It's an alias for
   :class:`py2:StringIO.StringIO` in Python 2 and :class:`py3:io.StringIO` in
   Python 3.


.. data:: BytesIO

   This is a fake file object for binary data.  In Python 2, it's an alias for
   :class:`py2:StringIO.StringIO`, but in Python 3, it's an alias for
   :class:`py3:io.BytesIO`.


Renamed modules and attributes compatibility
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

.. module:: six.moves
   :synopsis: Renamed modules and attributes compatibility

Python 3 reorganized the standard library and moved several functions to
different modules.  Six provides a consistent interface to them through the fake
:mod:`six.moves` module.  For example, to load the module for parsing HTML on
Python 2 or 3, write::

   from six.moves import html_parser

Similarly, to get the function to reload modules, which was moved from the
builtin module to the ``imp`` module, use::

   from six.moves import reload_module

For the most part, :mod:`six.moves` aliases are the names of the modules in
Python 3.  When the new Python 3 name is a package, the components of the name
are separated by underscores.  For example, ``html.parser`` becomes
``html_parser``.  In some cases where several modules have been combined, the
Python 2 name is retained.  This is so the appropiate modules can be found when
running on Python 2.  For example, ``BaseHTTPServer`` which is in
``http.server`` in Python 3 is aliased as ``BaseHTTPServer``.

Some modules which had two implementations have been merged in Python 3.  For
example, ``cPickle`` no longer exists in Python 3; it was merged with
``pickle``.  In these cases, fetching the fast version will load the fast one on
Python 2 and the merged module in Python 3.

The :mod:`py2:urllib`, :mod:`py2:urllib2`, and :mod:`py2:urlparse` modules have
been combined in the :mod:`py3:urllib` package in Python 3.  The
:mod:`six.moves.urllib` package is a version-independent location for this
functionality; its structure mimics the structure of the Python 3
:mod:`py3:urllib` package.

.. note::

   In order to make imports of the form::

     from six.moves.cPickle import loads

   work, six places special proxy objects in in :data:`py3:sys.modules`. These
   proxies lazily load the underlying module when an attribute is fetched. This
   will fail if the underlying module is not available in the Python
   interpreter. For example, ``sys.modules["six.moves.winreg"].LoadKey`` would
   fail on any non-Windows platform. Unfortunately, some applications try to
   load attributes on every module in :data:`py3:sys.modules`. six mitigates
   this problem for some applications by pretending attributes on unimportable
   modules don't exist. This hack doesn't work in every case, though. If you are
   encountering problems with the lazy modules and don't use any from imports
   directly from ``six.moves`` modules, you can workaround the issue by removing
   the six proxy modules::

     d = [name for name in sys.modules if name.startswith("six.moves.")]
     for name in d:
         del sys.modules[name]

Supported renames:

+------------------------------+-------------------------------------+-------------------------------------+
| Name                         | Python 2 name                       | Python 3 name                       |
+==============================+=====================================+=====================================+
| ``builtins``                 | :mod:`py2:__builtin__`              | :mod:`py3:builtins`                 |
+------------------------------+-------------------------------------+-------------------------------------+
| ``configparser``             | :mod:`py2:ConfigParser`             | :mod:`py3:configparser`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``copyreg``                  | :mod:`py2:copy_reg`                 | :mod:`py3:copyreg`                  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``cPickle``                  | :mod:`py2:cPickle`                  | :mod:`py3:pickle`                   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``cStringIO``                | :func:`py2:cStringIO.StringIO`      | :class:`py3:io.StringIO`            |
+------------------------------+-------------------------------------+-------------------------------------+
| ``dbm_gnu``                  | :func:`py2:gdbm`                    | :class:`py3:dbm.gnu`                |
+------------------------------+-------------------------------------+-------------------------------------+
| ``_dummy_thread``            | :mod:`py2:dummy_thread`             | :mod:`py3:_dummy_thread`            |
+------------------------------+-------------------------------------+-------------------------------------+
| ``email_mime_multipart``     | :mod:`py2:email.MIMEMultipart`      | :mod:`py3:email.mime.multipart`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``email_mime_nonmultipart``  | :mod:`py2:email.MIMENonMultipart`   | :mod:`py3:email.mime.nonmultipart`  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``email_mime_text``          | :mod:`py2:email.MIMEText`           | :mod:`py3:email.mime.text`          |
+------------------------------+-------------------------------------+-------------------------------------+
| ``email_mime_base``          | :mod:`py2:email.MIMEBase`           | :mod:`py3:email.mime.base`          |
+------------------------------+-------------------------------------+-------------------------------------+
| ``filter``                   | :func:`py2:itertools.ifilter`       | :func:`py3:filter`                  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``filterfalse``              | :func:`py2:itertools.ifilterfalse`  | :func:`py3:itertools.filterfalse`   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``http_cookiejar``           | :mod:`py2:cookielib`                | :mod:`py3:http.cookiejar`           |
+------------------------------+-------------------------------------+-------------------------------------+
| ``http_cookies``             | :mod:`py2:Cookie`                   | :mod:`py3:http.cookies`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``html_entities``            | :mod:`py2:htmlentitydefs`           | :mod:`py3:html.entities`            |
+------------------------------+-------------------------------------+-------------------------------------+
| ``html_parser``              | :mod:`py2:HTMLParser`               | :mod:`py3:html.parser`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``http_client``              | :mod:`py2:httplib`                  | :mod:`py3:http.client`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``BaseHTTPServer``           | :mod:`py2:BaseHTTPServer`           | :mod:`py3:http.server`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``CGIHTTPServer``            | :mod:`py2:CGIHTTPServer`            | :mod:`py3:http.server`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``SimpleHTTPServer``         | :mod:`py2:SimpleHTTPServer`         | :mod:`py3:http.server`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``input``                    | :func:`py2:raw_input`               | :func:`py3:input`                   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``intern``                   | :func:`py2:intern`                  | :func:`py3:sys.intern`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``map``                      | :func:`py2:itertools.imap`          | :func:`py3:map`                     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``queue``                    | :mod:`py2:Queue`                    | :mod:`py3:queue`                    |
+------------------------------+-------------------------------------+-------------------------------------+
| ``range``                    | :func:`py2:xrange`                  | :func:`py3:range`                   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``reduce``                   | :func:`py2:reduce`                  | :func:`py3:functools.reduce`        |
+------------------------------+-------------------------------------+-------------------------------------+
| ``reload_module``            | :func:`py2:reload`                  | :func:`py3:imp.reload`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``reprlib``                  | :mod:`py2:repr`                     | :mod:`py3:reprlib`                  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``shlex_quote``              | :mod:`py2:pipes.quote`              | :mod:`py3:shlex.quote`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``socketserver``             | :mod:`py2:SocketServer`             | :mod:`py3:socketserver`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``_thread``                  | :mod:`py2:thread`                   | :mod:`py3:_thread`                  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter``                  | :mod:`py2:Tkinter`                  | :mod:`py3:tkinter`                  |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_dialog``           | :mod:`py2:Dialog`                   | :mod:`py3:tkinter.dialog`           |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_filedialog``       | :mod:`py2:FileDialog`               | :mod:`py3:tkinter.FileDialog`       |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_scrolledtext``     | :mod:`py2:ScrolledText`             | :mod:`py3:tkinter.scrolledtext`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_simpledialog``     | :mod:`py2:SimpleDialog`             | :mod:`py3:tkinter.simpledialog`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_ttk``              | :mod:`py2:ttk`                      | :mod:`py3:tkinter.ttk`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_tix``              | :mod:`py2:Tix`                      | :mod:`py3:tkinter.tix`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_constants``        | :mod:`py2:Tkconstants`              | :mod:`py3:tkinter.constants`        |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_dnd``              | :mod:`py2:Tkdnd`                    | :mod:`py3:tkinter.dnd`              |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_colorchooser``     | :mod:`py2:tkColorChooser`           | :mod:`py3:tkinter.colorchooser`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_commondialog``     | :mod:`py2:tkCommonDialog`           | :mod:`py3:tkinter.commondialog`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_tkfiledialog``     | :mod:`py2:tkFileDialog`             | :mod:`py3:tkinter.filedialog`       |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_font``             | :mod:`py2:tkFont`                   | :mod:`py3:tkinter.font`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_messagebox``       | :mod:`py2:tkMessageBox`             | :mod:`py3:tkinter.messagebox`       |
+------------------------------+-------------------------------------+-------------------------------------+
| ``tkinter_tksimpledialog``   | :mod:`py2:tkSimpleDialog`           | :mod:`py3:tkinter.simpledialog`     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib.parse``             | See :mod:`six.moves.urllib.parse`   | :mod:`py3:urllib.parse`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib.error``             | See :mod:`six.moves.urllib.error`   | :mod:`py3:urllib.error`             |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib.request``           | See :mod:`six.moves.urllib.request` | :mod:`py3:urllib.request`           |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib.response``          | See :mod:`six.moves.urllib.response`| :mod:`py3:urllib.response`          |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib.robotparser``       | :mod:`py2:robotparser`              | :mod:`py3:urllib.robotparser`       |
+------------------------------+-------------------------------------+-------------------------------------+
| ``urllib_robotparser``       | :mod:`py2:robotparser`              | :mod:`py3:urllib.robotparser`       |
+------------------------------+-------------------------------------+-------------------------------------+
| ``UserDict``                 | :class:`py2:UserDict.UserDict`      | :class:`py3:collections.UserDict`   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``UserList``                 | :class:`py2:UserList.UserList`      | :class:`py3:collections.UserList`   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``UserString``               | :class:`py2:UserString.UserString`  | :class:`py3:collections.UserString` |
+------------------------------+-------------------------------------+-------------------------------------+
| ``winreg``                   | :mod:`py2:_winreg`                  | :mod:`py3:winreg`                   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``xmlrpc_client``            | :mod:`py2:xmlrpclib`                | :mod:`py3:xmlrpc.client`            |
+------------------------------+-------------------------------------+-------------------------------------+
| ``xmlrpc_server``            | :mod:`py2:SimpleXMLRPCServer`       | :mod:`py3:xmlrpc.server`            |
+------------------------------+-------------------------------------+-------------------------------------+
| ``xrange``                   | :func:`py2:xrange`                  | :func:`py3:range`                   |
+------------------------------+-------------------------------------+-------------------------------------+
| ``zip``                      | :func:`py2:itertools.izip`          | :func:`py3:zip`                     |
+------------------------------+-------------------------------------+-------------------------------------+
| ``zip_longest``              | :func:`py2:itertools.izip_longest`  | :func:`py3:itertools.zip_longest`   |
+------------------------------+-------------------------------------+-------------------------------------+

urllib parse
<<<<<<<<<<<<

.. module:: six.moves.urllib.parse
   :synopsis: Stuff from :mod:`py2:urlparse` and :mod:`py2:urllib` in Python 2 and :mod:`py3:urllib.parse` in Python 3

Contains functions from Python 3's :mod:`py3:urllib.parse` and Python 2's:

:mod:`py2:urlparse`:

* :func:`py2:urlparse.ParseResult`
* :func:`py2:urlparse.SplitResult`
* :func:`py2:urlparse.urlparse`
* :func:`py2:urlparse.urlunparse`
* :func:`py2:urlparse.parse_qs`
* :func:`py2:urlparse.parse_qsl`
* :func:`py2:urlparse.urljoin`
* :func:`py2:urlparse.urldefrag`
* :func:`py2:urlparse.urlsplit`
* :func:`py2:urlparse.urlunsplit`
* :func:`py2:urlparse.splitquery`
* :func:`py2:urlparse.uses_fragment`
* :func:`py2:urlparse.uses_netloc`
* :func:`py2:urlparse.uses_params`
* :func:`py2:urlparse.uses_query`
* :func:`py2:urlparse.uses_relative`

and :mod:`py2:urllib`:

* :func:`py2:urllib.quote`
* :func:`py2:urllib.quote_plus`
* :func:`py2:urllib.splittag`
* :func:`py2:urllib.splituser`
* :func:`py2:urllib.unquote`
* :func:`py2:urllib.unquote_plus`
* :func:`py2:urllib.urlencode`


urllib error
<<<<<<<<<<<<

.. module:: six.moves.urllib.error
   :synopsis: Stuff from :mod:`py2:urllib` and :mod:`py2:urllib2` in Python 2 and :mod:`py3:urllib.error` in Python 3

Contains exceptions from Python 3's :mod:`py3:urllib.error` and Python 2's:

:mod:`py2:urllib`:

* :exc:`py2:urllib.ContentTooShortError`

and :mod:`py2:urllib2`:

* :exc:`py2:urllib2.URLError`
* :exc:`py2:urllib2.HTTPError`


urllib request
<<<<<<<<<<<<<<

.. module:: six.moves.urllib.request
   :synopsis: Stuff from :mod:`py2:urllib` and :mod:`py2:urllib2` in Python 2 and :mod:`py3:urllib.request` in Python 3

Contains items from Python 3's :mod:`py3:urllib.request` and Python 2's:

:mod:`py2:urllib`:

* :func:`py2:urllib.pathname2url`
* :func:`py2:urllib.url2pathname`
* :func:`py2:urllib.getproxies`
* :func:`py2:urllib.urlretrieve`
* :func:`py2:urllib.urlcleanup`
* :class:`py2:urllib.URLopener`
* :class:`py2:urllib.FancyURLopener`
* :func:`py2:urllib.proxy_bypass`

and :mod:`py2:urllib2`:

* :func:`py2:urllib2.urlopen`
* :func:`py2:urllib2.install_opener`
* :func:`py2:urllib2.build_opener`
* :class:`py2:urllib2.Request`
* :class:`py2:urllib2.OpenerDirector`
* :class:`py2:urllib2.HTTPDefaultErrorHandler`
* :class:`py2:urllib2.HTTPRedirectHandler`
* :class:`py2:urllib2.HTTPCookieProcessor`
* :class:`py2:urllib2.ProxyHandler`
* :class:`py2:urllib2.BaseHandler`
* :class:`py2:urllib2.HTTPPasswordMgr`
* :class:`py2:urllib2.HTTPPasswordMgrWithDefaultRealm`
* :class:`py2:urllib2.AbstractBasicAuthHandler`
* :class:`py2:urllib2.HTTPBasicAuthHandler`
* :class:`py2:urllib2.ProxyBasicAuthHandler`
* :class:`py2:urllib2.AbstractDigestAuthHandler`
* :class:`py2:urllib2.HTTPDigestAuthHandler`
* :class:`py2:urllib2.ProxyDigestAuthHandler`
* :class:`py2:urllib2.HTTPHandler`
* :class:`py2:urllib2.HTTPSHandler`
* :class:`py2:urllib2.FileHandler`
* :class:`py2:urllib2.FTPHandler`
* :class:`py2:urllib2.CacheFTPHandler`
* :class:`py2:urllib2.UnknownHandler`
* :class:`py2:urllib2.HTTPErrorProcessor`


urllib response
<<<<<<<<<<<<<<<

.. module:: six.moves.urllib.response
   :synopsis: Stuff from :mod:`py2:urllib` in Python 2 and :mod:`py3:urllib.response` in Python 3

Contains classes from Python 3's :mod:`py3:urllib.response` and Python 2's:

:mod:`py2:urllib`:

* :class:`py2:urllib.addbase`
* :class:`py2:urllib.addclosehook`
* :class:`py2:urllib.addinfo`
* :class:`py2:urllib.addinfourl`


Advanced - Customizing renames
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

.. currentmodule:: six

It is possible to add additional names to the :mod:`six.moves` namespace.


.. function:: add_move(item)

   Add *item* to the :mod:`six.moves` mapping.  *item* should be a
   :class:`MovedAttribute` or :class:`MovedModule` instance.


.. function:: remove_move(name)

   Remove the :mod:`six.moves` mapping called *name*.  *name* should be a
   string.


Instances of the following classes can be passed to :func:`add_move`.  Neither
have any public members.


.. class:: MovedModule(name, old_mod, new_mod)

   Create a mapping for :mod:`six.moves` called *name* that references different
   modules in Python 2 and 3.  *old_mod* is the name of the Python 2 module.
   *new_mod* is the name of the Python 3 module.


.. class:: MovedAttribute(name, old_mod, new_mod, old_attr=None, new_attr=None)

   Create a mapping for :mod:`six.moves` called *name* that references different
   attributes in Python 2 and 3.  *old_mod* is the name of the Python 2 module.
   *new_mod* is the name of the Python 3 module.  If *new_attr* is not given, it
   defaults to *old_attr*.  If neither is given, they both default to *name*.