Merge pull request #9907 from Carreau/docs-py-2

Add warning on documentation for stop of python 2 support.

docs/source/conf.py

@@ -1,284 +1,298 b''
 # -*- coding: utf-8 -*-
 #
 # IPython documentation build configuration file.
 
 # NOTE: This file has been edited manually from the auto-generated one from
 # sphinx.  Do NOT delete and re-generate.  If any changes from sphinx are
 # needed, generate a scratch one and merge by hand any new fields needed.
 
 #
 # This file is execfile()d with the current directory set to its containing dir.
 #
 # The contents of this file are pickled, so don't put values in the namespace
 # that aren't pickleable (module imports are okay, they're removed automatically).
 #
 # All configuration values have a default value; values that are commented out
 # serve to show the default value.
 
 import sys, os
 
 ON_RTD = os.environ.get('READTHEDOCS', None) == 'True'
 
 if ON_RTD:
     # Mock the presence of matplotlib, which we don't have on RTD
     # see
     # http://read-the-docs.readthedocs.io/en/latest/faq.html
     tags.add('rtd')
 
     # RTD doesn't use the Makefile, so re-run autogen_{things}.py here.
     for name in ('config', 'api', 'magics', 'shortcuts'):
         fname = 'autogen_{}.py'.format(name)
         fpath = os.path.abspath(os.path.join('..', fname))
         with open(fpath) as f:
             exec(compile(f.read(), fname, 'exec'), {
                 '__file__': fpath,
                 '__name__': '__main__',
             })
 else:
     import sphinx_rtd_theme
     html_theme = "sphinx_rtd_theme"
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # If your extensions are in another directory, add it here. If the directory
 # is relative to the documentation root, use os.path.abspath to make it
 # absolute, like shown here.
 sys.path.insert(0, os.path.abspath('../sphinxext'))
 
 # We load the ipython release info into a dict by explicit execution
 iprelease = {}
 exec(compile(open('../../IPython/core/release.py').read(), '../../IPython/core/release.py', 'exec'),iprelease)
 
 # General configuration
 # ---------------------
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
     'matplotlib.sphinxext.mathmpl',
     'matplotlib.sphinxext.only_directives',
     'matplotlib.sphinxext.plot_directive',
     'sphinx.ext.autodoc',
     'sphinx.ext.autosummary',
     'sphinx.ext.doctest',
     'sphinx.ext.inheritance_diagram',
     'sphinx.ext.intersphinx',
     'IPython.sphinxext.ipython_console_highlighting',
     'IPython.sphinxext.ipython_directive',
     'sphinx.ext.napoleon',  # to preprocess docstrings
     'github',  # for easy GitHub links
     'magics',
 ]
 
 if ON_RTD:
     # Remove extensions not currently supported on RTD
     extensions.remove('matplotlib.sphinxext.only_directives')
     extensions.remove('matplotlib.sphinxext.mathmpl')
     extensions.remove('matplotlib.sphinxext.plot_directive')
     extensions.remove('IPython.sphinxext.ipython_directive')
     extensions.remove('IPython.sphinxext.ipython_console_highlighting')
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
 # The suffix of source filenames.
 source_suffix = '.rst'
 
+rst_prolog = ''
+
 def is_stable(extra):
     for ext in {'dev', 'b', 'rc'}:
         if ext in extra:
             return False
     return True
 
 if is_stable(iprelease['_version_extra']):
     tags.add('ipystable')
 else:
     tags.add('ipydev')
-    rst_prolog = """
-    .. warning::
+    rst_prolog += """
+.. warning::
+
+    This documentation covers a development version of IPython. The development
+    version may differ significantly from the latest stable release.
+"""
+
+rst_prolog += """
+.. important::
+
+    This documentation covers IPython versions 6.0 and higher. Beginning with
+    version 6.0, IPython stopped supporting compatibility with Python versions
+    lower than 3.3 including all versions of Python 2.7.
 
-        This documentation is for a development version of IPython. There may be
-        significant differences from the latest stable release.
+    If you are looking for an IPython version compatible with Python 2.7,
+    please use the IPython 5.x LTS release and refer to its documentation (LTS
+    is the long term support release).
 
-    """
+"""
 
 # The master toctree document.
 master_doc = 'index'
 
 # General substitutions.
 project = 'IPython'
 copyright = 'The IPython Development Team'
 
 # ghissue config
 github_project_url = "https://github.com/ipython/ipython"
 
 # numpydoc config
 numpydoc_show_class_members = False # Otherwise Sphinx emits thousands of warnings
 numpydoc_class_members_toctree = False
 
 # The default replacements for |version| and |release|, also used in various
 # other places throughout the built documents.
 #
 # The full version, including alpha/beta/rc tags.
 release = "%s" % iprelease['version']
 # Just the X.Y.Z part, no '-dev'
 version = iprelease['version'].split('-', 1)[0]
 
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
 #today = ''
 # Else, today_fmt is used as the format for a strftime call.
 today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
 #unused_docs = []
 
 # Exclude these glob-style patterns when looking for source files. They are
 # relative to the source/ directory.
 exclude_patterns = ['whatsnew/pr']
 
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
 #add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
 #add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
 #show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
 # Set the default role so we can use `foo` instead of ``foo``
 default_role = 'literal'
 
 # Options for HTML output
 # -----------------------
 
 # The style sheet to use for HTML and HTML Help pages. A file of that name
 # must exist either in Sphinx' static/ path, or in one of the custom paths
 # given in html_static_path.
 # html_style = 'default.css'
 
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
 #html_title = None
 
 # The name of an image file (within the static path) to place at the top of
 # the sidebar.
 #html_logo = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
 # Favicon needs the directory name
 html_favicon = '_static/favicon.ico'
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
 html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 #html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
 #html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
 html_additional_pages = {
     'interactive/htmlnotebook': 'notebook_redirect.html',
     'interactive/notebook': 'notebook_redirect.html',
     'interactive/nbconvert': 'notebook_redirect.html',
     'interactive/public_server': 'notebook_redirect.html',
 }
 
 # If false, no module index is generated.
 #html_use_modindex = True
 
 # If true, the reST sources are included in the HTML build as _sources/<name>.
 #html_copy_source = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
 #html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
 #html_file_suffix = ''
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'ipythondoc'
 
 intersphinx_mapping = {'python': ('https://docs.python.org/3/', None),
                        'rpy2': ('https://rpy2.readthedocs.io/en/version_2.8.x/', None),
                        'traitlets': ('https://traitlets.readthedocs.io/en/latest/', None),
                        'jupyterclient': ('https://jupyter-client.readthedocs.io/en/latest/', None),
                        'ipyparallel': ('https://ipyparallel.readthedocs.io/en/latest/', None),
                        'jupyter': ('https://jupyter.readthedocs.io/en/latest/', None),
                       }
 
 # Options for LaTeX output
 # ------------------------
 
 # The paper size ('letter' or 'a4').
 latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
 latex_font_size = '11pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, document class [howto/manual]).
 
 latex_documents = [
     ('index', 'ipython.tex', 'IPython Documentation',
      u"""The IPython Development Team""", 'manual', True),
     ('parallel/winhpc_index', 'winhpc_whitepaper.tex',
      'Using IPython on Windows HPC Server 2008',
      u"Brian E. Granger", 'manual', True)
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
 #latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
 #latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
 #latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
 #latex_appendices = []
 
 # If false, no module index is generated.
 latex_use_modindex = True
 
 
 # Options for texinfo output
 # --------------------------
 
 texinfo_documents = [
   (master_doc, 'ipython', 'IPython Documentation',
    'The IPython Development Team',
    'IPython',
    'IPython Documentation',
    'Programming',
    1),
 ]
 
 modindex_common_prefix = ['IPython.']
 
 
 # Cleanup
 # -------
 # delete release info to avoid pickling errors from sphinx
 
 del iprelease

docs/source/coredev/release_process.rst

@@ -1,246 +1,252 b''
 .. _release_process:
 
 =======================
 IPython release process
 =======================
 
 This document contains the process that is used to create an IPython release.
 
 Conveniently, the ``release`` script in the ``tools`` directory of the ``IPython``
 repository automates most of the release process. This document serves as a
 handy reminder and checklist for the release manager. 
 
 During the release process, you might need the extra following dependencies:
 
  - ``keyring`` to access your GitHub authentication tokens
  - ``graphviz`` to generate some graphs in the documentation
  
 Make sure you have all the required dependencies to run the tests as well.
  
 
 1. Set Environment variables
 ----------------------------
 
 Set environment variables to document previous release tag, current
 release milestone, current release version, and git tag.
 
 These variables may be used later to copy/paste as answers to the script
 questions instead of typing the appropriate command when the time comes. These
 variables are not used by the scripts directly; therefore, there is no need to
 ``export`` them. The format for bash is as follows, but note that these values
 are just an example valid only for the 5.0 release; you'll need to update them
 for the release you are actually making::
 
     PREV_RELEASE=4.2.1
     MILESTONE=5.0
     VERSION=5.0.0
     BRANCH=master
 
 
 2. Create GitHub stats and finish release note
 ----------------------------------------------
 
 .. note::
 
     This step is optional if making a Beta or RC release.
 
 .. note::
 
     Before generating the GitHub stats, verify that all closed issues and pull
     requests have `appropriate milestones
     <https://github.com/ipython/ipython/wiki/Dev%3A-GitHub-workflow#milestones>`_.
     `This search
     <https://github.com/ipython/ipython/issues?q=is%3Aclosed+no%3Amilestone+is%3Aissue>`_
     should return no results before creating the GitHub stats.
 
 If a major release:
 
     - merge any pull request notes into what's new::
 
           python tools/update_whatsnew.py
 
     - update ``docs/source/whatsnew/development.rst``, to ensure it covers
       the major release features
 
     - move the contents of ``development.rst`` to ``versionX.rst`` where ``X`` is
       the numerical release version
 
     - generate summary of GitHub contributions, which can be done with::
 
           python tools/github_stats.py --milestone $MILESTONE > stats.rst
 
       which may need some manual cleanup of ``stats.rst``. Add the cleaned
       ``stats.rst`` results to ``docs/source/whatsnew/github-stats-X.rst``
       where ``X`` is the numerical release version (don't forget to add it to
       the git repo as well). If creating a major release, make a new
       ``github-stats-X.rst`` file; if creating a minor release, the content
       from ``stats.rst`` may simply be added to the top of an existing
       ``github-stats-X.rst`` file.  Finally, edit
       ``docs/source/whatsnew/index.rst`` to list the new ``github-stats-X``
       file you just created and remove temporarily the first entry called
       ``development`` (you'll need to add it back after release).
 
       Make sure that the stats file has a header or it won't be rendered in
       the final documentation. 
 
 To find duplicates and update `.mailmap`, use::
 
     git log --format="%aN <%aE>" $PREV_RELEASE... | sort -u -f
 
 3. Make sure the repository is clean
 ------------------------------------
 
 of any file that could be problematic.
    Remove all non-tracked files with:
 
    .. code::
 
        git clean -xfdi
 
    This will ask for confirmation before removing all untracked files. Make
    sure the ``dist/`` folder is clean to avoid any stale builds from
    previous build attempts.
 
 
 4. Update the release version number
 ------------------------------------
 
 Edit ``IPython/core/release.py`` to have the current version.
 
 in particular, update version number and ``_version_extra`` content in
 ``IPython/core/release.py``.
 
 Step 5 will validate your changes automatically, but you might still want to
 make sure the version number matches pep440.
 
 In particular, ``rc`` and ``beta`` are not separated by ``.`` or the ``sdist``
 and ``bdist`` will appear as different releases. For example, a valid version
 number for a release candidate (rc) release is: ``1.3rc1``. Notice that there
 is no separator between the '3' and the 'r'. Check the environment variable
 ``$VERSION`` as well.
 
 You will likely just have to modify/comment/uncomment one of the lines setting
 ``_version_extra``
 
 
 5. Run the `tools/build_release` script
 ---------------------------------------
 
 Running ``tools/build_release`` does all the file checking and building that
 the real release script will do. This makes test installations, checks that
 the build procedure runs OK, and tests other steps in the release process.
 
 The ``build_release`` script will in particular verify that the version number
 match PEP 440, in order to avoid surprise at the time of build upload.
 
 We encourage creating a test build of the docs as well.
 
 6. Create and push the new tag
 ------------------------------
 
 Commit the changes to release.py::
 
     git commit -am "release $VERSION"
     git push origin $BRANCH
 
 Create and push the tag::
 
     git tag -am "release $VERSION" "$VERSION"
     git push origin --tags
 
 Update release.py back to ``x.y-dev`` or ``x.y-maint``, and re-add the
 ``development`` entry in ``docs/source/whatsnew/index.rst`` and push::
 
     git commit -am "back to development"
     git push origin $BRANCH
 
 7. Get a fresh clone
 --------------------
 
 Get a fresh clone of the tag for building the release::
 
     cd /tmp
     git clone --depth 1 https://github.com/ipython/ipython.git -b "$VERSION"
     cd ipython
 
 .. note::
 
     You can aslo cleanup the current working repository with ``git clean -xfdi``
 
 8. Run the release script
 -------------------------
 
+.. important::
+
+    These steps cover instructions for creating releases of IPython 5.x LTS and
+    IPython 6.x. Ignore release steps for Python 2 when releasing IPython 6.x
+    which no longer supports Python 2. 
+
 Run the ``release`` script, this step requires having a current wheel, Python
 >=3.4 and Python 2.7.::
 
     ./tools/release
 
 This makes the tarballs and wheels, and puts them under the ``dist/``
 folder. Be sure to test the ``wheels``  and the ``sdist`` locally before
 uploading them to PyPI. We do not use an universal wheel as each wheel
 installs an ``ipython2`` or ``ipython3`` script, depending on the version of
 Python it is built for. Using an universal wheel would prevent this.
 
 Use the following to actually upload the result of the build::
 
     ./tools/release upload
 
 It should posts them to ``archive.ipython.org``.
 
 You will need to use `twine <https://github.com/pypa/twine>`_ ) manually to
 actually upload on PyPI. Unlike setuptools, twine is able to upload packages
-over SSL.
+over SSL::
 
     twine upload dist/*
 
 
 PyPI/Warehouse will automatically hide previous releases. If you are uploading
 a non-stable version, make sure to log-in to PyPI and un-hide previous version.
 
 
 9. Draft a short release announcement
 -------------------------------------
 
 The announcement should include:
 
 - release highlights
 - a link to the html version of the *What's new* section of the documentation
 - a link to upgrade or installation tips (if necessary)
 
 Post the announcement to the mailing list and or blog, and link from Twitter.
 
 .. note::
 
     If you are doing a RC or Beta, you can likely skip the next steps.
 
 10. Update milestones on GitHub
 -------------------------------
 
 These steps will bring milestones up to date:
 
 - close the just released milestone
 - open a new milestone for the next release (x, y+1), if the milestone doesn't
   exist already
 
 11. Update the IPython website
 ------------------------------
 
 The IPython website should document the new release:
 
 - add release announcement (news, announcements)
 - update current version and download links
 - update links on the documentation page (especially if a major release)
 
 12. Update readthedocs
 ----------------------
 
 Make sure to update readthedocs and set the latest tag as stable, as well as
 checking that previous release is still building under its own tag. 
 
 
 13. Celebrate!
 --------------
 
 Celebrate the release and please thank the contributors for their work. Great
 job!
 

docs/source/overview.rst

@@ -1,255 +1,256 b''
 .. _overview:
 
 ========
 Overview
 ========
 
 One of Python's most useful features is its interactive interpreter.
 It allows for very fast testing of ideas without the overhead of
 creating test files as is typical in most programming languages.
 However, the interpreter supplied with the standard Python distribution
 is somewhat limited for extended interactive use.
 
 The goal of IPython is to create a comprehensive environment for
 interactive and exploratory computing.  To support this goal, IPython
 has three main components:
 
 * An enhanced interactive Python shell.
 
 * A decoupled :ref:`two-process communication model <ipythonzmq>`, which
   allows for multiple clients to connect to a computation kernel, most notably
   the web-based notebook provided with `Jupyter <https://jupyter.org>`_.
 
 * An architecture for interactive parallel computing now part of the
   `ipyparallel` package.
 
 All of IPython is open source (released under the revised BSD license).
 
 Enhanced interactive Python shell
 =================================
 
 IPython's interactive shell (:command:`ipython`), has the following goals,
 amongst others:
 
 1. Provide an interactive shell superior to Python's default. IPython
    has many features for tab-completion, object introspection, system shell
    access, command history retrieval across sessions, and its own special
    command system for adding functionality when working interactively. It
    tries to be a very efficient environment both for Python code development
    and for exploration of problems using Python objects (in situations like
    data analysis).
   
 2. Serve as an embeddable, ready to use interpreter for your own
    programs. An interactive IPython shell can be started with a single call
    from inside another program, providing access to the current namespace.
    This can be very useful both for debugging purposes and for situations
    where a blend of batch-processing and interactive exploration are needed.
   
 3. Offer a flexible framework which can be used as the base
    environment for working with other systems, with Python as the underlying
    bridge language. Specifically scientific environments like Mathematica,
    IDL and Matlab inspired its design, but similar ideas can be
    useful in many fields.
   
 4. Allow interactive testing of threaded graphical toolkits. IPython
    has support for interactive, non-blocking control of GTK, Qt, WX, GLUT, and
    OS X applications via special threading flags. The normal Python
    shell can only do this for Tkinter applications.
 
 Main features of the interactive shell
 --------------------------------------
 
 * Dynamic object introspection. One can access docstrings, function
   definition prototypes, source code, source files and other details
   of any object accessible to the interpreter with a single
   keystroke (:samp:`?`, and using :samp:`??` provides additional detail).
   
 * Searching through modules and namespaces with :samp:`*` wildcards, both
   when using the :samp:`?` system and via the :samp:`%psearch` command.
 
 * Completion in the local namespace, by typing :kbd:`TAB` at the prompt.
   This works for keywords, modules, methods, variables and files in the
   current directory. This is supported via the ``prompt_toolkit`` library.
   Custom completers can be implemented easily for different purposes
   (system commands, magic arguments etc.)
 
 * Numbered input/output prompts with command history (persistent
   across sessions and tied to each profile), full searching in this
   history and caching of all input and output.
 
 * User-extensible 'magic' commands. A set of commands prefixed with
   :samp:`%`  or :samp:`%%` is available for controlling IPython itself and provides
   directory control, namespace information and many aliases to
   common system shell commands.
 
 * Alias facility for defining your own system aliases.
 
 * Complete system shell access. Lines starting with :samp:`!` are passed
   directly to the system shell, and using :samp:`!!` or :samp:`var = !cmd` 
   captures shell output into python variables for further use.
 
 * The ability to expand python variables when calling the system shell. In a
   shell command, any python variable prefixed with :samp:`$` is expanded. A
   double :samp:`$$` allows passing a literal :samp:`$` to the shell (for access
   to shell and environment variables like :envvar:`PATH`).
 
 * Filesystem navigation, via a magic :samp:`%cd` command, along with a
   persistent bookmark system (using :samp:`%bookmark`) for fast access to
   frequently visited directories.
 
 * A lightweight persistence framework via the :samp:`%store` command, which
   allows you to save arbitrary Python variables. These get restored
   when you run the :samp:`%store -r` command.
 
 * Automatic indentation and highlighting of code as you type (through the
   `prompt_toolkit` library).
 
 * Macro system for quickly re-executing multiple lines of previous
   input with a single name via the :samp:`%macro` command. Macros can be
   stored persistently via :samp:`%store` and edited via :samp:`%edit`.
 
 * Session logging (you can then later use these logs as code in your
   programs). Logs can optionally timestamp all input, and also store
   session output (marked as comments, so the log remains valid
   Python source code).
 
 * Session restoring: logs can be replayed to restore a previous
   session to the state where you left it.
 
 * Verbose and colored exception traceback printouts. Easier to parse
   visually, and in verbose mode they produce a lot of useful
   debugging information (basically a terminal version of the cgitb
   module).
 
 * Auto-parentheses via the :samp:`%autocall` command: callable objects can be
   executed without parentheses: :samp:`sin 3` is automatically converted to
   :samp:`sin(3)`
 
 * Auto-quoting: using :samp:`,`, or :samp:`;` as the first character forces
   auto-quoting of the rest of the line: :samp:`,my_function a b` becomes
   automatically :samp:`my_function("a","b")`, while :samp:`;my_function a b`
   becomes :samp:`my_function("a b")`.
 
 * Extensible input syntax. You can define filters that pre-process
   user input to simplify input in special situations. This allows
   for example pasting multi-line code fragments which start with
   :samp:`>>>` or :samp:`...` such as those from other python sessions or the
   standard Python documentation.
 
 * Flexible :ref:`configuration system <config_overview>`. It uses a
   configuration file which allows permanent setting of all command-line
   options, module loading, code and file execution. The system allows
   recursive file inclusion, so you can have a base file with defaults and
   layers which load other customizations for particular projects.
 
 * Embeddable. You can call IPython as a python shell inside your own
   python programs. This can be used both for debugging code or for
   providing interactive abilities to your programs with knowledge
   about the local namespaces (very useful in debugging and data
   analysis situations).
 
 * Easy debugger access. You can set IPython to call up an enhanced version of
   the Python debugger (pdb) every time there is an uncaught exception. This
   drops you inside the code which triggered the exception with all the data
   live and it is possible to navigate the stack to rapidly isolate the source
   of a bug. The :samp:`%run` magic command (with the :samp:`-d` option) can run
   any script under pdb's control, automatically setting initial breakpoints for
   you.  This version of pdb has IPython-specific improvements, including
   tab-completion and traceback coloring support. For even easier debugger
   access, try :samp:`%debug` after seeing an exception.
 
 * Profiler support. You can run single statements (similar to
   :samp:`profile.run()`) or complete programs under the profiler's control.
   While this is possible with standard cProfile or profile modules,
   IPython wraps this functionality with magic commands (see :samp:`%prun`
   and :samp:`%run -p`) convenient for rapid interactive work.
 
 * Simple timing information. You can use the :samp:`%timeit` command to get
   the execution time of a Python statement or expression. This machinery is
   intelligent enough to do more repetitions for commands that finish very
   quickly in order to get a better estimate of their running time. 
 
 .. sourcecode:: ipython
 
     In [1]: %timeit 1+1
     10000000 loops, best of 3: 25.5 ns per loop
 
     In [2]: %timeit [math.sin(x) for x in range(5000)]
     1000 loops, best of 3: 719 µs per loop
 
 .. 
 
   To get the timing information for more than one expression, use the
   :samp:`%%timeit` cell magic command.
   
 
 * Doctest support. The special :samp:`%doctest_mode` command toggles a mode
   to use doctest-compatible prompts, so you can use IPython sessions as
   doctest code. By default, IPython also allows you to paste existing
   doctests, and strips out the leading :samp:`>>>` and :samp:`...` prompts in
   them.
 
 .. _ipythonzmq:
 
 Decoupled two-process model
 ==============================
 
 IPython has abstracted and extended the notion of a traditional
 *Read-Evaluate-Print Loop* (REPL) environment by decoupling the *evaluation*
 into its own process. We call this process a **kernel**: it receives execution
 instructions from clients and communicates the results back to them.
 
 This decoupling allows us to have several clients connected to the same
 kernel, and even allows clients and kernels to live on different machines.
 With the exclusion of the traditional single process terminal-based IPython
 (what you start if you run ``ipython`` without any subcommands), all
 other IPython machinery uses this two-process model. Most of this is now part
 of the `Jupyter` project, whis includes ``jupyter console``,  ``jupyter
 qtconsole``, and ``jupyter notebook``.
 
 As an example, this means that when you start ``jupyter qtconsole``, you're
 really starting two processes, a kernel and a Qt-based client can send
 commands to and receive results from that kernel. If there is already a kernel
 running that you want to connect to, you can pass the  ``--existing`` flag
 which will skip initiating a new kernel and connect to the most recent kernel,
 instead. To connect to a specific kernel once you have several kernels
 running, use the ``%connect_info`` magic to get the unique connection file,
 which will be something like ``--existing kernel-19732.json`` but with
 different numbers which correspond to the Process ID of the kernel.
 
 You can read more about using `jupyter qtconsole 
 <http://jupyter.org/qtconsole/>`_, and
 `jupyter notebook <http://jupyter-notebook.readthedocs.io/en/latest/>`_. There
 is also a :ref:`message spec <messaging>` which documents the protocol for 
 communication between kernels
 and clients.
 
 .. seealso::
     
     `Frontend/Kernel Model`_ example notebook
 
 
 Interactive parallel computing
 ==============================
 
     
 This functionality is optional and now part of the `ipyparallel
 <http://ipyparallel.readthedocs.io/>`_ project.
 
 Portability and Python requirements
 -----------------------------------
 
-As of the 2.0 release, IPython works with Python 2.7 and 3.3 or above.
+Version 6.0+ supports compatibility with Python 3.3 and higher.
+Versions 2.0 to 5.x work with Python 2.7.x releases and Python 3.3 and higher.
 Version 1.0 additionally worked with Python 2.6 and 3.2.
 Version 0.12 was the first version to fully support Python 3.
 
 IPython is known to work on the following operating systems:
 
 	* Linux
 	* Most other Unix-like OSs (AIX, Solaris, BSD, etc.)
 	* Mac OS X
 	* Windows (CygWin, XP, Vista, etc.)
 
 See :ref:`here <install_index>` for instructions on how to install IPython.
 
 .. include:: links.txt