Start working on whatsnew notes for 7.19.

docs/source/whatsnew/version7.rst

@@ -1,1163 +1,1193 b''
 ============
  7.x Series
 ============
 
+.. _version 719:
+
+IPython 7.19
+============
+
+IPython 7.19 accumulative two month of works, bug fixes and improvements, there
+was exceptionally no release last month.
+
+  - Fix to restore the ability to specify more than one extension using command
+    line flags when using traitlets 5.0 :ghpull:`12543`
+  - Docs docs formatting that make the install commands work on zsh
+    :ghpull:`12587`
+  - Always display the last frame in tracebacks even if hidden with
+    ``__traceback_hide__`` :ghpull:`12601`
+  - Avoid an issue where a callback can be registered multiple times.
+    :ghpull:`12625`
+  - Avoid an issue in debugger mode where frames changes could be lost.
+    :ghpull:`12627`
+
+  - Never hide the frames that invoke a debugger, even if marked as hidden by
+    ``__traceback_hide__`` :ghpull:`12631`
+  - Fix calling the debugger in a recursive manner :ghpull:`12659`
+
+
+A number of code changes have landed on master and we are getting close to
+enough new features and codebase improvement that a 8.0 start to make sens.
+For downstream packages, please start working on migrating downstream testing
+away from iptest and using pytest, as nose will not work on Python 3.10 and we
+will likely start removing it as a dependency for testing.
+
 .. _version 718:
 
 IPython 7.18
 ============
 
 IPython 7.18 is a minor release that mostly contains bugfixes.
 
  - ``CRLF`` is now handled by magics my default; solving some issues due to copy
    pasting on windows. :ghpull:`12475`
 
  - Requiring pexpect ``>=4.3`` as we are Python 3.7+ only and earlier version of
    pexpect will be incompatible. :ghpull:`12510`
 
  - Minimum jedi version is now 0.16. :ghpull:`12488`
 
 
 
 .. _version 717:
 
 IPython 7.17
 ============
 
 IPython 7.17 brings a couple of new improvements to API and a couple of user
 facing changes to make the terminal experience more user friendly. 
 
 :ghpull:`12407` introduces the ability to pass extra argument to the IPython
 debugger class; this is to help a new project from ``kmaork``
 (https://github.com/kmaork/madbg) to feature a fully remote debugger.
 
 :ghpull:`12410` finally remove support for 3.6, while the codebase is still
 technically compatible; IPython will not install on Python 3.6.
 
 lots of work on the debugger and hidden frames from ``@impact27`` in
 :ghpull:`12437`, :ghpull:`12445`, :ghpull:`12460` and in particular
 :ghpull:`12453` which make the debug magic more robust at handling spaces.
 
 Biggest API addition is code transformation which is done before code execution;
 IPython allows a number of hooks to catch non-valid Python syntax (magic, prompt
 stripping...etc). Transformers are usually called many time; typically:
 
  - When trying to figure out whether the code is complete and valid (should we
    insert a new line or execute ?)
  - During actual code execution pass before giving the code to Python's
    ``exec``.
 
 This lead to issues when transformer might have had side effects; or do external
 queries. Starting with IPython 7.17 you can expect your transformer to be called
 less time.
 
 Input transformers are now called only once in the execution path of
 `InteractiveShell`, allowing to register transformer that potentially have side
 effects (note that this is not recommended). Internal methods `should_run_async`, and
 `run_cell_async` now take a recommended optional `transformed_cell`, and
 `preprocessing_exc_tuple` parameters that will become mandatory at some point in
 the future; that is to say cells need to be explicitly transformed to be valid
 Python syntax ahead of trying to run them. :ghpull:`12440`;
 
 ``input_transformers`` can now also have an attribute ``has_side_effects`` set
 to `True`, when this attribute is present; this  will prevent the transformers
 from being ran when IPython is trying to guess whether the user input is
 complete. Note that this may means you will need to explicitly execute in some
 case where your transformations are now not ran; but will not affect users with
 no custom extensions.
 
 
 API Changes
 -----------
 
 Change of API and exposed objects automatically detected using `frappuccino
 <https://pypi.org/project/frappuccino/>`_
 
 
  The following items are new since 7.16.0::
 
      + IPython.core.interactiveshell.InteractiveShell.get_local_scope(self, stack_depth)
 
  The following signatures differ since 7.16.0::
 
      - IPython.core.interactiveshell.InteractiveShell.run_cell_async(self, raw_cell, store_history=False, silent=False, shell_futures=True)
      + IPython.core.interactiveshell.InteractiveShell.run_cell_async(self, raw_cell, store_history=False, silent=False, shell_futures=True, *, transformed_cell=None, preprocessing_exc_tuple=None)
 
      - IPython.core.interactiveshell.InteractiveShell.should_run_async(self, raw_cell)
      + IPython.core.interactiveshell.InteractiveShell.should_run_async(self, raw_cell, *, transformed_cell=None, preprocessing_exc_tuple=None)
 
      - IPython.terminal.debugger.TerminalPdb.pt_init(self)
      + IPython.terminal.debugger.TerminalPdb.pt_init(self, pt_session_options=None)
 
 This method was added::
 
      + IPython.core.interactiveshell.InteractiveShell.get_local_scope
 
 Which is now also present on subclasses::
 
      + IPython.terminal.embed.InteractiveShellEmbed.get_local_scope
      + IPython.terminal.interactiveshell.TerminalInteractiveShell.get_local_scope
 
 
 .. _version 716:
 
 IPython 7.16
 ============
 
 
 The default traceback mode will now skip frames that are marked with
 ``__tracebackhide__ = True`` and show how many traceback frames have been
 skipped. This can be toggled by using :magic:`xmode` with the ``--show`` or
 ``--hide`` attribute. It will have no effect on non verbose traceback modes.
 
 The ipython debugger also now understands ``__tracebackhide__`` as well and will
 skip hidden frames when displaying. Movement up and down the stack will skip the
 hidden frames and will show how many frames were hidden. Internal IPython frames
 are also now hidden by default. The behavior can be changed with the
 ``skip_hidden`` while in the debugger, command and accepts "yes", "no", "true"
 and "false" case insensitive parameters.
 
 
 Misc Noticeable changes:
 ------------------------
 
 - Exceptions are now (re)raised when running notebooks via the :magic:`%run`, helping to catch issues in workflows and
   pipelines. :ghpull:`12301`
 - Fix inputhook for qt 5.15.0 :ghpull:`12355`
 - Fix wx inputhook :ghpull:`12375`
 - Add handling for malformed pathext env var (Windows) :ghpull:`12367`
 - use $SHELL in system_piped :ghpull:`12360` for uniform behavior with
   ipykernel.
 
 Reproducible Build
 ------------------
 
 IPython 7.15 reproducible build did not work, so we try again this month
 :ghpull:`12358`.
 
 
 API Changes
 -----------
 
 Change of API and exposed objects automatically detected using `frappuccino
 <https://pypi.org/project/frappuccino/>`_ (still in beta):
 
 
 The following items are new and mostly related to understanding ``__tracebackbhide__``::
 
     + IPython.core.debugger.Pdb.do_down(self, arg)
     + IPython.core.debugger.Pdb.do_skip_hidden(self, arg)
     + IPython.core.debugger.Pdb.do_up(self, arg)
     + IPython.core.debugger.Pdb.hidden_frames(self, stack)
     + IPython.core.debugger.Pdb.stop_here(self, frame)
 
 
 The following items have been removed::
 
     - IPython.core.debugger.Pdb.new_do_down
     - IPython.core.debugger.Pdb.new_do_up
 
 Those were implementation details.
 
 
 .. _version 715:
 
 IPython 7.15
 ============
 
 IPython 7.15 brings a number of bug fixes and user facing improvements.
 
 Misc Noticeable changes:
 ------------------------
 
  - Long completion name have better elision in terminal :ghpull:`12284`
  - I've started to test on Python 3.9 :ghpull:`12307` and fix some errors.
  - Hi DPI scaling of figures when using qt eventloop :ghpull:`12314`
  - Document the ability to have systemwide configuration for IPython.
    :ghpull:`12328`
  - Fix issues with input autoformatting :ghpull:`12336`
  - ``IPython.core.debugger.Pdb`` is now interruptible (:ghpull:`12168`, in 7.14
    but forgotten in release notes)
  - Video HTML attributes (:ghpull:`12212`, in 7.14 but forgotten in release
    notes)
 
 Reproducible Build
 ------------------
 
 Starting with IPython 7.15, I am attempting to provide reproducible builds,
 that is to say you should be able from the source tree to generate an sdist
 and wheel that are identical byte for byte with the publish version on PyPI.
 
 I've only tested on a couple of machines so far and the process is relatively
 straightforward, so this mean that IPython not only have a deterministic build
 process, but also I have either removed, or put under control all effects of
 the build environments on the final artifact.  I encourage you to attempt the
 build process on your machine as documented in :ref:`core_developer_guide`
 and let me know if you do not obtain an identical artifact.
 
 While reproducible builds is critical to check that the supply chain of (open
 source) software has not been compromised, it can also help to speedup many
 of the build processes in large environment (conda, apt...) by allowing
 better caching of intermediate build steps.
 
 Learn more on `<https://reproducible-builds.org/>`_. `Reflections on trusting
 trust <https://dl.acm.org/doi/10.1145/358198.358210>`_ is also one of the
 cornerstone and recommended reads on this subject.
 
 .. note::
 
    The build commit from which the sdist is generated is also `signed
    <https://en.wikipedia.org/wiki/Digital_signature>`_, so you should be able to
    check it has not been compromised, and the git repository is a `merkle-tree
    <https://en.wikipedia.org/wiki/Merkle_tree>`_, you can check the consistency
    with `git-fsck <https://git-scm.com/docs/git-fsck>`_ which you likely `want
    to enable by default
    <https://gist.github.com/mbbx6spp/14b86437e794bffb4120>`_.
 
 NEP29: Last version to support Python 3.6
 -----------------------------------------
 
 IPython 7.15 will be the Last IPython version to officially support Python
 3.6, as stated by `NumPy Enhancement Proposal 29
 <https://numpy.org/neps/nep-0029-deprecation_policy.html>`_. Starting with
 next minor version of IPython I may stop testing on Python 3.6 and may stop
 publishing release artifacts that install on Python 3.6
 
 Highlighted features
 --------------------
 
 Highlighted features are not new, but seem to not be widely known, this
 section will help you discover in more narrative form what you can do with
 IPython.
 
 Increase Tab Completion Menu Height
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 In terminal IPython it is possible to increase the hight of the tab-completion
 menu. To do so set the value of
 :configtrait:`TerminalInteractiveShell.space_for_menu`, this will reserve more
 space at the bottom of the screen for various kind of menus in IPython including
 tab completion and searching in history. 
 
 Autoformat Code in the terminal
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 If you have a preferred code formatter, you can configure IPython to
 reformat your code. Set the value of
 :configtrait:`TerminalInteractiveShell.autoformatter` to for example ``'black'``
 and IPython will auto format your code when possible.
 
 
 .. _version 714:
 
 IPython 7.14
 ============
 
 IPython  7.14 is a minor release that fix a couple of bugs and prepare
 compatibility with new or future versions of some libraries. 
 
 Important changes:
 ------------------
 
  - Fix compatibility with Sphinx 3+ :ghpull:`12235`
  - Remove deprecated matplotlib parameter usage, compatibility with matplotlib
    3.3+ :`122250`
 
 Misc Changes
 ------------
 
  - set ``.py`` extension when editing current buffer in vi/emacs. :ghpull:`12167`
  - support for unicode identifiers in ``?``/``??`` :ghpull:`12208`
  - add extra options to the ``Video`` Rich objects :ghpull:`12212`
  - add pretty-printing to ``SimpleNamespace`` :ghpull:`12230`
 
 IPython.core.debugger.Pdb is now interruptible
 ----------------------------------------------
 
 A ``KeyboardInterrupt`` will now interrupt IPython's extended debugger, in order to make Jupyter able to interrupt it. (:ghpull:`12168`)
 
 Video HTML attributes
 ---------------------
 
 Add an option to `IPython.display.Video` to change the attributes of the HTML display of the video (:ghpull:`12212`)
 
 
 Pending deprecated imports
 --------------------------
 
 Many object present in ``IPython.core.display`` are there for internal use only,
 and should  already been imported from ``IPython.display`` by users and external
 libraries. Trying to import those from ``IPython.core.display`` is still possible
 but will trigger a
 deprecation warning in later versions of IPython and will become errors in the
 future. 
 
 This will simplify compatibility with other Python kernels (like Xeus-Python),
 and simplify code base. 
 
 
 
 
 .. _version 713:
 
 IPython 7.13
 ============
 
 IPython 7.13 is the final release of the 7.x branch since master is diverging
 toward an 8.0. Exiting new features have already been merged in 8.0 and will
 not be available on the 7.x branch. All the changes below have been backported
 from the master branch.
 
 
  - Fix inability to run PDB when inside an event loop :ghpull:`12141`
  - Fix ability to interrupt some processes on windows :ghpull:`12137`
  - Fix debugger shortcuts :ghpull:`12132`
  - improve tab completion when inside a string by removing irrelevant elements :ghpull:`12128`
  - Fix display of filename tab completion when the path is long :ghpull:`12122`
  - Many removal of Python 2 specific code path :ghpull:`12110`
  - displaying wav files do not require NumPy anymore, and is 5x to 30x faster :ghpull:`12113`
 
 See the list of all closed issues and pull request on `github
 <https://github.com/ipython/ipython/pulls?q=is%3Aclosed+milestone%3A7.13>`_.
 
 .. _version 712:
 
 IPython 7.12
 ============
 
 IPython 7.12 is a minor update that mostly brings code cleanup, removal of
 longtime deprecated function and a couple update to documentation cleanup as well.
 
 Notable changes are the following:
 
  - Exit non-zero when ipython is given a file path to run that doesn't exist :ghpull:`12074`
  - Test PR on ARM64 with Travis-CI :ghpull:`12073`
  - Update CI to work with latest Pytest :ghpull:`12086`
  - Add infrastructure to run ipykernel eventloop via trio :ghpull:`12097`
  - Support git blame ignore revs :ghpull:`12091`
  - Start multi-line ``__repr__`` s on their own line :ghpull:`12099`
 
 .. _version 7111:
 
 IPython 7.11.1
 ==============
 
 A couple of deprecated functions (no-op) have been reintroduces in py3compat as
 Cython was still relying on them, and will be removed in a couple of versions.
 
 .. _version 711:
 
 IPython 7.11
 ============
 
 IPython 7.11 received a couple of compatibility fixes and code cleanup.
 
 A number of function in the ``py3compat`` have been removed; a number of types
 in the IPython code base are now non-ambiguous and now always ``unicode``
 instead of ``Union[Unicode,bytes]``; many of the relevant code path have thus
 been simplified/cleaned and types annotation added.
 
 IPython support several verbosity level from exceptions. ``xmode plain`` now
 support chained exceptions. :ghpull:`11999`
 
 We are starting to remove ``shell=True`` in some usages of subprocess. While not directly
 a security issue (as IPython is made to run arbitrary code anyway) it is not good
 practice and we'd like to show the example. :ghissue:`12023`. This discussion
 was started by ``@mschwager`` thanks to a new auditing tool they are working on
 with duo-labs (`dlint <https://github.com/duo-labs/dlint>`_).
 
 Work around some bugs in Python 3.9 tokenizer :ghpull:`12057`
 
 IPython will now print its version after a crash. :ghpull:`11986`
 
 This is likely the last release from the 7.x series that will see new feature.
 The master branch will soon accept large code changes and thrilling new
 features; the 7.x branch will only start to accept critical bug fixes, and
 update dependencies.
 
 .. _version 7102:
 
 IPython 7.10.2
 ==============
 
 IPython 7.10.2 fix a couple of extra incompatibility between IPython, ipdb,
 asyncio and Prompt Toolkit 3.
 
 .. _version 7101:
 
 IPython 7.10.1
 ==============
 
 IPython 7.10.1 fix a couple of incompatibilities with Prompt toolkit 3 (please
 update Prompt toolkit to 3.0.2 at least), and fixes some interaction with
 headless IPython.
 
 .. _version 7100:
 
 IPython 7.10.0
 ==============
 
 IPython 7.10 is the first double digit minor release in the  last decade, and
 first since the release of IPython 1.0, previous double digit minor release was
 in August 2009.
 
 We've been trying to give you regular release on the last Friday of every month
 for a guaranty of rapid access to bug fixes and new features.
 
 Unlike the previous first few releases that have seen only a couple of code
 changes, 7.10 bring a number of changes, new features and bugfixes.
 
 Stop Support for Python 3.5 – Adopt NEP 29
 ------------------------------------------
 
 IPython has decided to follow the informational `NEP 29
 <https://numpy.org/neps/nep-0029-deprecation_policy.html>`_ which layout a clear
 policy as to which version of (C)Python and NumPy are supported.
 
 We thus dropped support for Python 3.5, and cleaned up a number of code path
 that were Python-version dependant. If you are on 3.5 or earlier pip should
 automatically give you the latest compatible version of IPython so you do not
 need to pin to a given version.
 
 Support for Prompt Toolkit 3.0
 ------------------------------
 
 Prompt Toolkit 3.0 was release a week before IPython 7.10 and introduces a few
 breaking changes. We believe IPython 7.10 should be compatible with both Prompt
 Toolkit 2.x and 3.x, though it has not been extensively tested with 3.x so
 please report any issues.
 
 
 Prompt Rendering Performance improvements
 -----------------------------------------
 
 Pull Request :ghpull:`11933` introduced an optimisation in the prompt rendering
 logic that should decrease the resource usage of IPython when using the
 _default_ configuration but could potentially introduce a regression of
 functionalities if you are using a custom prompt.
 
 We know assume if you haven't changed the default keybindings that the prompt
 **will not change** during the duration of your input – which is for example
 not true when using vi insert mode that switches between `[ins]` and `[nor]`
 for the current mode.
 
 If you are experiencing any issue let us know.
 
 Code autoformatting
 -------------------
 
 The IPython terminal can now auto format your code just before entering a new
 line or executing a command. To do so use the
 ``--TerminalInteractiveShell.autoformatter`` option and set it to ``'black'``;
 if black is installed IPython will use black to format your code when possible.
 
 IPython cannot always properly format your code; in particular it will
 auto formatting with *black* will only work if:
 
    - Your code does not contains magics or special python syntax.
 
    - There is no code after your cursor.
 
 The Black API is also still in motion; so this may not work with all versions of
 black.
 
 It should be possible to register custom formatter, though the API is till in
 flux.
 
 Arbitrary Mimetypes Handing in Terminal (Aka inline images in terminal)
 -----------------------------------------------------------------------
 
 When using IPython terminal it is now possible to register function to handle
 arbitrary mimetypes. While rendering non-text based representation was possible in
 many jupyter frontend; it was not possible in terminal IPython, as usually
 terminal are limited to displaying text. As many terminal these days provide
 escape sequences to display non-text; bringing this loved feature to IPython CLI
 made a lot of sens. This functionality will not only allow inline images; but
 allow opening of external program; for example ``mplayer`` to "display" sound
 files.
 
 So far only the hooks necessary for this are in place, but no default mime
 renderers added; so inline images will only be available via extensions. We will
 progressively enable these features by default in the next few releases, and
 contribution is welcomed.
 
 We welcome any feedback on the API. See :ref:`shell_mimerenderer` for more
 informations.
 
 This is originally based on work form in :ghpull:`10610` from @stephanh42
 started over two years ago, and still a lot need to be done.
 
 MISC
 ----
 
  - Completions can define their own ordering :ghpull:`11855`
  - Enable Plotting in the same cell than the one that import matplotlib
    :ghpull:`11916`
  - Allow to store and restore multiple variables at once :ghpull:`11930`
 
 You can see `all pull-requests <https://github.com/ipython/ipython/pulls?q=is%3Apr+milestone%3A7.10+is%3Aclosed>`_ for this release.
 
 API Changes
 -----------
 
 Change of API and exposed objects automatically detected using `frappuccino <https://pypi.org/project/frappuccino/>`_ (still in beta):
 
 The following items are new in IPython 7.10::
 
     + IPython.terminal.shortcuts.reformat_text_before_cursor(buffer, document, shell)
     + IPython.terminal.interactiveshell.PTK3
     + IPython.terminal.interactiveshell.black_reformat_handler(text_before_cursor)
     + IPython.terminal.prompts.RichPromptDisplayHook.write_format_data(self, format_dict, md_dict='None')
 
 The following items have been removed in 7.10::
 
     - IPython.lib.pretty.DICT_IS_ORDERED
 
 The following signatures differ between versions::
 
     - IPython.extensions.storemagic.restore_aliases(ip)
     + IPython.extensions.storemagic.restore_aliases(ip, alias='None')
 
 Special Thanks
 --------------
 
  - @stephanh42 who started the work on inline images in terminal 2 years ago
  - @augustogoulart who spent a lot of time triaging issues and responding to
    users.
  - @con-f-use who is my (@Carreau) first sponsor on GitHub, as a reminder if you
    like IPython, Jupyter and many other library of the SciPy stack you can
    donate to numfocus.org non profit
 
 .. _version 790:
 
 IPython 7.9.0
 =============
 
 IPython 7.9 is a small release with a couple of improvement and bug fixes.
 
  - Xterm terminal title should be restored on exit :ghpull:`11910`
  - special variables ``_``,``__``, ``___`` are not set anymore when cache size
    is 0 or less.  :ghpull:`11877`
  - Autoreload should have regained some speed by using a new heuristic logic to
    find all objects needing reload. This should avoid large objects traversal
    like pandas dataframes. :ghpull:`11876`
  - Get ready for Python 4. :ghpull:`11874`
  - `%env` Magic now has heuristic to hide potentially sensitive values :ghpull:`11896`
 
 This is a small release despite a number of Pull Request Pending that need to
 be reviewed/worked on. Many of the core developers have been busy outside of
 IPython/Jupyter and we thanks all contributor for their patience; we'll work on
 these as soon as we have time.
 
 
 .. _version780:
 
 IPython 7.8.0
 =============
 
 IPython 7.8.0 contain a few bugfix and 2 new APIs:
 
  - Enable changing the font color for LaTeX rendering :ghpull:`11840`
  - and Re-Expose some PDB API (see below)
 
 Expose Pdb API
 --------------
 
 Expose the built-in ``pdb.Pdb`` API. ``Pdb`` constructor arguments are generically
 exposed, regardless of python version.
 Newly exposed arguments:
 
 - ``skip`` - Python 3.1+
 - ``nosiginnt`` - Python 3.2+
 - ``readrc`` - Python 3.6+
 
 Try it out::
 
     from IPython.terminal.debugger import TerminalPdb
     pdb = TerminalPdb(skip=["skipthismodule"])
 
 
 See :ghpull:`11840`
 
 .. _version770:
 
 IPython 7.7.0
 =============
 
 IPython 7.7.0 contain multiple bug fixes and documentation updates; Here are a
 few of the outstanding issue fixed:
 
    - Fix a bug introduced in 7.6 where the ``%matplotlib`` magic would fail on
      previously acceptable arguments :ghpull:`11814`.
    - Fix the manage location on freebsd :ghpull:`11808`.
    - Fix error message about aliases after ``%reset`` call in ipykernel
      :ghpull:`11806`
    - Fix Duplication completions in emacs :ghpull:`11803`
 
 We are planning to adopt `NEP29 <https://github.com/numpy/numpy/pull/14086>`_
 (still currently in draft) which may make this minor version of IPython the
 last one to support Python 3.5 and will make the code base more aggressive
 toward removing compatibility with older versions of Python.
 
 GitHub now support to give only "Triage" permissions to users; if you'd like to
 help close stale issues and labels issues please reach to us with your GitHub
 Username and we'll add you to the triage team. It is a great way to start
 contributing and a path toward getting commit rights.
 
 .. _version761:
 
 IPython 7.6.1
 =============
 
 IPython 7.6.1 contain a critical bugfix in the ``%timeit`` magic, which would
 crash on some inputs as a side effect of :ghpull:`11716`. See :ghpull:`11812`
 
 
 .. _whatsnew760:
 
 IPython 7.6.0
 =============
 
 IPython 7.6.0 contains a couple of bug fixes and number of small features
 additions as well as some compatibility with the current development version of
 Python 3.8.
 
    - Add a ``-l`` option to :magic:`psearch` to list the available search
      types. :ghpull:`11672`
    - Support ``PathLike`` for ``DisplayObject`` and ``Image``. :ghpull:`11764`
    - Configurability of timeout in the test suite for slow platforms.
      :ghpull:`11756`
    - Accept any casing for matplotlib backend. :ghpull:`121748`
    - Properly skip test that requires numpy to be installed :ghpull:`11723`
    - More support for Python 3.8 and positional only arguments (pep570)
      :ghpull:`11720`
    - Unicode names for the completion are loaded lazily on first use which
      should decrease startup time. :ghpull:`11693`
    - Autoreload now update the types of reloaded objects; this for example allow
      pickling of reloaded objects. :ghpull:`11644`
    - Fix a bug where ``%%time`` magic would suppress cell output. :ghpull:`11716`
 
 
 Prepare migration to pytest (instead of nose) for testing
 ---------------------------------------------------------
 
 Most of the work between 7.5 and 7.6 was to prepare the migration from our
 testing framework to pytest. Most of the test suite should now work by simply
 issuing ``pytest`` from the root of the repository.
 
 The migration to pytest is just at its beginning. Many of our test still rely
 on IPython-specific plugins for nose using pytest (doctest using IPython syntax
 is one example of this where test appear as "passing", while no code has been
 ran). Many test also need to be updated like ``yield-test`` to be properly
 parametrized tests.
 
 Migration to pytest allowed me to discover a number of issues in our test
 suite; which was hiding a number of subtle issues – or not actually running
 some of the tests in our test suite – I have thus corrected many of those; like
 improperly closed resources; or used of deprecated features. I also made use of
 the ``pytest --durations=...`` to find some of our slowest test and speed them
 up (our test suite can now be up to 10% faster). Pytest as also a variety of
 plugins and flags which will make the code quality of IPython and the testing
 experience better.
 
 Misc
 ----
 
 We skipped the release of 7.6 at the end of May, but will attempt to get back
 on schedule. We are starting to think about making introducing backward
 incompatible change and start the 8.0 series.
 
 Special Thanks to Gabriel (@gpotter2 on GitHub), who among other took care many
 of the remaining task for 7.4 and 7.5, like updating the website.
 
 .. _whatsnew750:
 
 IPython 7.5.0
 =============
 
 IPython 7.5.0 consist mostly of bug-fixes, and documentation updates, with one
 minor new feature. The `Audio` display element can now be assigned an element
 id when displayed in browser. See :ghpull:`11670`
 
 The major outstanding bug fix correct a change of behavior that was introduce
 in 7.4.0 where some cell magics would not be able to access or modify global
 scope when using the ``@needs_local_scope`` decorator. This was typically
 encountered with the ``%%time`` and ``%%timeit`` magics. See :ghissue:`11659`
 and :ghpull:`11698`.
 
 .. _whatsnew740:
 
 IPython 7.4.0
 =============
 
 Unicode name completions
 ------------------------
 
 Previously, we provided completion for a unicode name with its relative symbol.
 With this, now IPython provides complete suggestions to unicode name symbols.
 
 As on the PR, if user types ``\LAT<tab>``, IPython provides a list of
 possible completions. In this case, it would be something like::
 
    'LATIN CAPITAL LETTER A',
    'LATIN CAPITAL LETTER B',
    'LATIN CAPITAL LETTER C',
    'LATIN CAPITAL LETTER D',
    ....
 
 This help to type unicode character that do not have short latex aliases, and
 have long unicode names. for example ``Ͱ``, ``\GREEK CAPITAL LETTER HETA``.
 
 This feature was contributed by Luciana Marques :ghpull:`11583`.
 
 Make audio normalization optional
 ---------------------------------
 
 Added 'normalize' argument to `IPython.display.Audio`. This argument applies
 when audio data is given as an array of samples. The default of `normalize=True`
 preserves prior behavior of normalizing the audio to the maximum possible range.
 Setting to `False` disables normalization.
 
 
 Miscellaneous
 -------------
 
  - Fix improper acceptation of ``return`` outside of functions. :ghpull:`11641`.
  - Fixed PyQt 5.11 backwards incompatibility causing sip import failure.
    :ghpull:`11613`.
  - Fix Bug where ``type?`` would crash IPython. :ghpull:`1608`.
  - Allow to apply ``@needs_local_scope`` to cell magics for convenience.
    :ghpull:`11542`.
 
 .. _whatsnew730:
 
 IPython 7.3.0
 =============
 
 .. _whatsnew720:
 
 IPython 7.3.0 bring several bug fixes and small improvements that you will
 described bellow. 
 
 The biggest change to this release is the implementation of the ``%conda`` and
 ``%pip`` magics, that will attempt to install packages in the **current
 environment**. You may still need to restart your interpreter or kernel for the
 change to be taken into account, but it should simplify installation of packages
 into remote environment. Installing using pip/conda from the command line is
 still the prefer method.
 
 The ``%pip`` magic was already present, but was only printing a warning; now it
 will actually forward commands to pip. 
 
 Misc bug fixes and improvements:
 
  - Compatibility with Python 3.8.
  - Do not expand shell variable in execution magics, and added the
    ``no_var_expand`` decorator for magic requiring a similar functionality
    :ghpull:`11516`
  - Add ``%pip`` and ``%conda`` magic :ghpull:`11524`
  - Re-initialize posix aliases after a ``%reset`` :ghpull:`11528`
  - Allow the IPython command line to run ``*.ipynb`` files :ghpull:`11529`
 
 IPython 7.2.0
 =============
 
 IPython 7.2.0 brings minor bugfixes, improvements, and new configuration options:
 
  - Fix a bug preventing PySide2 GUI integration from working :ghpull:`11464`
  - Run CI on Mac OS ! :ghpull:`11471`
  - Fix IPython "Demo" mode. :ghpull:`11498`
  - Fix ``%run`` magic  with path in name :ghpull:`11499`
  - Fix: add CWD to sys.path *after* stdlib :ghpull:`11502`
  - Better rendering of signatures, especially long ones. :ghpull:`11505`
  - Re-enable jedi by default if it's installed :ghpull:`11506`
  - Add New ``minimal`` exception reporting mode (useful for educational purpose). See :ghpull:`11509`
 
 
 Added ability to show subclasses when using pinfo and other utilities
 ---------------------------------------------------------------------
 
 When using ``?``/``??`` on a class, IPython will now list the first 10 subclasses.
 
 Special Thanks to Chris Mentzel of the Moore Foundation for this feature. Chris
 is one of the people who played a critical role in IPython/Jupyter getting
 funding.
 
 We are grateful for all the help Chris has given us over the years,
 and we're now proud to have code contributed by Chris in IPython.
 
 OSMagics.cd_force_quiet configuration option
 --------------------------------------------
 
 You can set this option to force the %cd magic to behave as if ``-q`` was passed:
 ::
 
     In [1]: cd /
     /
 
     In [2]: %config OSMagics.cd_force_quiet = True
 
     In [3]: cd /tmp
 
     In [4]:
 
 See :ghpull:`11491`
 
 In vi editing mode, whether the prompt includes the current vi mode can now be configured
 -----------------------------------------------------------------------------------------
 
 Set the ``TerminalInteractiveShell.prompt_includes_vi_mode`` to a boolean value
 (default: True) to control this feature. See :ghpull:`11492`
 
 .. _whatsnew710:
 
 IPython 7.1.0
 =============
 
 IPython 7.1.0 is the first minor release after 7.0.0 and mostly brings fixes to
 new features, internal refactoring, and fixes for regressions that happened during the 6.x->7.x
 transition. It also brings **Compatibility with Python 3.7.1**, as we're
 unwillingly relying on a bug in CPython.
 
 New Core Dev:
 
  - We welcome Jonathan Slenders to the commiters. Jonathan has done a fantastic
    work on prompt_toolkit, and we'd like to recognise his impact by giving him
    commit rights. :ghissue:`11397`
 
 Notable Changes
 
  - Major update of "latex to unicode" tab completion map (see below)
 
 Notable New Features:
 
  - Restore functionality and documentation of the **sphinx directive**, which
    is now stricter (fail on error by daefault), has new configuration options,
    has a brand new documentation page :ref:`ipython_directive` (which needs
    some cleanup). It is also now *tested* so we hope to have less regressions.
    :ghpull:`11402`
 
  - ``IPython.display.Video`` now supports ``width`` and ``height`` arguments,
    allowing a custom width and height to be set instead of using the video's
    width and height. :ghpull:`11353`
 
  - Warn when using ``HTML('<iframe>')`` instead of ``IFrame`` :ghpull:`11350`
 
  - Allow Dynamic switching of editing mode between vi/emacs and show
    normal/input mode in prompt when using vi. :ghpull:`11390`. Use ``%config
    TerminalInteractiveShell.editing_mode = 'vi'`` or ``%config
    TerminalInteractiveShell.editing_mode = 'emacs'`` to dynamically switch
    between modes.
 
 
 Notable Fixes:
 
  - Fix entering of **multi-line blocks in terminal** IPython, and various
    crashes in the new input transformation machinery :ghpull:`11354`,
    :ghpull:`11356`, :ghpull:`11358`. These also fix a **Compatibility bug
    with Python 3.7.1**.
 
  - Fix moving through generator stack in ipdb :ghpull:`11266`
 
  - %Magic command arguments now support quoting. :ghpull:`11330`
 
  - Re-add ``rprint`` and ``rprinte`` aliases. :ghpull:`11331`
 
  - Remove implicit dependency on ``ipython_genutils`` :ghpull:`11317`
 
  - Make ``nonlocal`` raise ``SyntaxError`` instead of silently failing in async
    mode. :ghpull:`11382`
 
  - Fix mishandling of magics and ``= !`` assignment just after a dedent in
    nested code blocks :ghpull:`11418`
 
  - Fix instructions for custom shortcuts :ghpull:`11426`
 
 
 Notable Internals improvements:
 
  - Use of ``os.scandir`` (Python 3 only) to speed up some file system operations.
    :ghpull:`11365`
 
  - use ``perf_counter`` instead of ``clock`` for more precise
    timing results with ``%time`` :ghpull:`11376`
 
 Many thanks to all the contributors and in particular to ``bartskowron`` and
 ``tonyfast`` who handled some pretty complicated bugs in the input machinery. We
 had a number of first time contributors and maybe hacktoberfest participants that
 made significant contributions and helped us free some time to focus on more
 complicated bugs.
 
 You
 can see all the closed issues and Merged PR, new features and fixes `here
 <https://github.com/ipython/ipython/issues?utf8=%E2%9C%93&q=+is%3Aclosed+milestone%3A7.1+>`_.
 
 Unicode Completion update
 -------------------------
 
 In IPython 7.1 the Unicode completion map has been updated and synchronized with
 the Julia language.
 
 Added and removed character characters:
 
  ``\jmath`` (``ȷ``), ``\\underleftrightarrow`` (U+034D, combining) have been
  added, while ``\\textasciicaron`` have been removed
 
 Some sequences have seen their prefix removed:
 
  - 6 characters ``\text...<tab>`` should now be inputed with ``\...<tab>`` directly,
  - 45 characters ``\Elz...<tab>`` should now be inputed with ``\...<tab>`` directly,
  - 65 characters ``\B...<tab>`` should now be inputed with ``\...<tab>`` directly,
  - 450 characters ``\m...<tab>`` should now be inputed with ``\...<tab>`` directly,
 
 Some sequences have seen their prefix shortened:
 
  - 5 characters ``\mitBbb...<tab>`` should now be inputed with ``\bbi...<tab>`` directly,
  - 52 characters ``\mit...<tab>`` should now be inputed with ``\i...<tab>`` directly,
  - 216 characters ``\mbfit...<tab>`` should now be inputed with ``\bi...<tab>`` directly,
  - 222 characters ``\mbf...<tab>`` should now be inputed with ``\b...<tab>`` directly,
 
 A couple of characters had their sequence simplified:
 
  - ``ð``, type ``\dh<tab>``, instead of ``\eth<tab>``
  - ``ħ``, type ``\hbar<tab>``, instead of ``\Elzxh<tab>``
  - ``ɸ``, type ``\ltphi<tab>``, instead of ``\textphi<tab>``
  - ``ϴ``, type ``\varTheta<tab>``, instead of ``\textTheta<tab>``
  - ``ℇ``, type ``\eulermascheroni<tab>``, instead of ``\Eulerconst<tab>``
  - ``ℎ``, type ``\planck<tab>``, instead of ``\Planckconst<tab>``
 
  - U+0336 (COMBINING LONG STROKE OVERLAY), type ``\strike<tab>``, instead of ``\Elzbar<tab>``.
 
 A couple of sequences have been updated:
 
  - ``\varepsilon`` now gives ``ɛ`` (GREEK SMALL LETTER EPSILON) instead of ``ε`` (GREEK LUNATE EPSILON SYMBOL),
  - ``\underbar`` now gives U+0331 (COMBINING MACRON BELOW) instead of U+0332 (COMBINING LOW LINE).
 
 
 .. _whatsnew700:
 
 IPython 7.0.0
 =============
 
 Released Thursday September 27th, 2018
 
 IPython 7 includes major feature improvements.
 This is also the second major version of IPython to support only
 Python 3 – starting at Python 3.4. Python 2 is still community-supported
 on the bugfix only 5.x branch, but we remind you that Python 2 "end of life"
 is on Jan 1st 2020.
 
 We were able to backport bug fixes to the 5.x branch thanks to our backport bot which
 backported more than `70 Pull-Requests
 <https://github.com/ipython/ipython/pulls?page=3&q=is%3Apr+sort%3Aupdated-desc+author%3Aapp%2Fmeeseeksdev++5.x&utf8=%E2%9C%93>`_, but there are still many PRs that required manual work. This is an area of the project where you can easily contribute by looking for `PRs that still need manual backport <https://github.com/ipython/ipython/issues?q=label%3A%22Still+Needs+Manual+Backport%22+is%3Aclosed+sort%3Aupdated-desc>`_
 
 The IPython 6.x branch will likely not see any further release unless critical
 bugs are found.
 
 Make sure you have pip > 9.0 before upgrading. You should be able to update by running:
 
 .. code::
 
     pip install ipython --upgrade
 
 .. only:: ipydev
 
   If you are trying to install or update an ``alpha``, ``beta``, or ``rc``
   version, use pip ``--pre`` flag.
 
   .. code::
 
       pip install ipython --upgrade --pre
 
 
 Or, if you have conda installed: 
 
 .. code::
    
    conda install ipython
 
 
 
 Prompt Toolkit 2.0
 ------------------
 
 IPython 7.0+ now uses ``prompt_toolkit 2.0``. If you still need to use an earlier
 ``prompt_toolkit`` version, you may need to pin IPython to ``<7.0``.
 
 Autowait: Asynchronous REPL
 ---------------------------
 
 Staring with IPython 7.0 on Python 3.6+, IPython can automatically ``await``
 top level code. You should not need to access an event loop or runner
 yourself. To learn more, read the :ref:`autoawait` section of our docs, see
 :ghpull:`11265`, or try the following code::
 
     Python 3.6.0
     Type 'copyright', 'credits' or 'license' for more information
     IPython 7.0.0 -- An enhanced Interactive Python. Type '?' for help.
 
     In [1]: import aiohttp
        ...: result = aiohttp.get('https://api.github.com')
 
     In [2]: response = await result
     <pause for a few 100s ms>
 
     In [3]: await response.json()
     Out[3]:
     {'authorizations_url': 'https://api.github.com/authorizations',
      'code_search_url': 'https://api.github.com/search/code?q={query}{&page,per_page,sort,order}',
     ...
     }
 
 .. note::
 
    Async integration is experimental code, behavior may change or be removed
    between Python and IPython versions without warnings.
 
 Integration is by default with `asyncio`, but other libraries can be configured --
 like ``curio`` or ``trio`` -- to improve concurrency in the REPL::
 
     In [1]: %autoawait trio
 
     In [2]: import trio
 
     In [3]: async def child(i):
        ...:     print("   child %s goes to sleep"%i)
        ...:     await trio.sleep(2)
        ...:     print("   child %s wakes up"%i)
 
     In [4]: print('parent start')
        ...: async with trio.open_nursery() as n:
        ...:     for i in range(3):
        ...:         n.spawn(child, i)
        ...: print('parent end')
     parent start
        child 2 goes to sleep
        child 0 goes to sleep
        child 1 goes to sleep
        <about 2 seconds pause>
        child 2 wakes up
        child 1 wakes up
        child 0 wakes up
     parent end
 
 See :ref:`autoawait` for more information.
 
 
 Asynchronous code in a Notebook interface or any other frontend using the
 Jupyter Protocol will require further updates to the IPykernel package.
 
 Non-Asynchronous code
 ~~~~~~~~~~~~~~~~~~~~~
 
 As the internal API of IPython is now asynchronous, IPython needs to run under
 an event loop. In order to allow many workflows, (like using the :magic:`%run`
 magic, or copy-pasting code that explicitly starts/stop event loop), when
 top-level code is detected as not being asynchronous, IPython code is advanced
 via a pseudo-synchronous runner, and may not advance pending tasks.
 
 Change to Nested Embed
 ~~~~~~~~~~~~~~~~~~~~~~
 
 The introduction of the ability to run async code had some effect on the
 ``IPython.embed()`` API. By default, embed will not allow you to run asynchronous
 code unless an event loop is specified.
 
 Effects on Magics
 ~~~~~~~~~~~~~~~~~
 
 Some magics will not work with async until they're updated.
 Contributions welcome.
 
 Expected Future changes
 ~~~~~~~~~~~~~~~~~~~~~~~
 
 We expect more internal but public IPython functions to become ``async``, and
 will likely end up having a persistent event loop while IPython is running.
 
 Thanks
 ~~~~~~
 
 This release took more than a year in the making.
 The code was rebased a number of
 times; leading to commit authorship that may have been lost in the final
 Pull-Request. Huge thanks to many people for contribution, discussion, code,
 documentation, use-cases: dalejung, danielballan, ellisonbg, fperez, gnestor,
 minrk, njsmith, pganssle, tacaswell, takluyver , vidartf ... And many others.
 
 
 Autoreload Improvement
 ----------------------
 
 The magic :magic:`%autoreload 2 <autoreload>` now captures new methods added to
 classes. Earlier, only methods existing as of the initial import were being
 tracked and updated.  
 
 This new feature helps dual environment development - Jupyter+IDE - where the
 code gradually moves from notebook cells to package files as it gets
 structured.
 
 **Example**: An instance of the class ``MyClass`` will be able to access the
 method ``cube()`` after it is uncommented and the file ``file1.py`` is saved on
 disk.
 
 
 .. code::
 
    # notebook
 
    from mymodule import MyClass
    first = MyClass(5)
 
 .. code::
 
    # mymodule/file1.py
 
    class MyClass:
 
        def __init__(self, a=10):
            self.a = a
 
        def square(self):
            print('compute square')
            return self.a*self.a
 
        # def cube(self):
        #     print('compute cube')
        #     return self.a*self.a*self.a
 
 
 
 
 Misc
 ----
 
 The autoindent feature that was deprecated in 5.x was re-enabled and
 un-deprecated in :ghpull:`11257`
 
 Make :magic:`%run -n -i ... <run>` work correctly. Earlier, if :magic:`%run` was
 passed both arguments, ``-n`` would be silently ignored. See :ghpull:`10308`
 
 
 The :cellmagic:`%%script` (as well as :cellmagic:`%%bash`,
 :cellmagic:`%%ruby`... ) cell magics now raise by default if the return code of
 the given code is non-zero (thus halting execution of further cells in a
 notebook). The behavior can be disable by passing the ``--no-raise-error`` flag.
 
 
 Deprecations
 ------------
 
 A couple of unused functions and methods have been deprecated and will be removed
 in future versions:
 
   - ``IPython.utils.io.raw_print_err``
   - ``IPython.utils.io.raw_print``
 
   
 Backwards incompatible changes
 ------------------------------
 
 * The API for transforming input before it is parsed as Python code has been
   completely redesigned: any custom input transformations will need to be
   rewritten. See :doc:`/config/inputtransforms` for details of the new API.