Development version
This document describes in-flight development work.
Warning
Please do not edit this file by hand (doing so will likely cause merge conflicts for other Pull Requests). Instead, create a new file in the docs/source/whatsnew/pr folder
Released .... ...., 2017
Need to be updated:
IPython 6 feature a major improvement in the completion machinery which is now capable of completing non-executed code. It is also the first version of IPython to stop compatibility with Python 2, which is still supported on the bugfix only 5.x branch. Read below to have a non-exhaustive list of new features.
Make sure you have pip > 9.0 before upgrading. You should be able to update by using:
pip install ipython --upgrade
New completion API and Interface
The completer Completion API has seen an overhaul, and the new completer have plenty of improvement both from the end users of terminal IPython or for consumers of the API.
This new API is capable of pulling completions from :any:`jedi`, thus allowing type inference on non-executed code. If :any:`jedi` is installed completion like the following are now becoming possible without code evaluation:
>>> data = ['Number of users', 123_456] ... data[0].<tab>
That is to say, IPython is now capable of inferring that data[0] is a string, and will suggest completions like .capitalize. The completion power of IPython will increase with new Jedi releases, and a number of bugs and more completions are already available on development version of :any:`jedi` if you are curious.
With the help of prompt toolkit, types of completions can be shown in the completer interface:
The appearance of the completer is controlled by the c.TerminalInteractiveShell.display_completions option that will show the type differently depending on the value among 'column', 'multicolumn' and 'readlinelike'
The use of Jedi also full fill a number of request and fix a number of bugs like case insensitive completion, completion after division operator: See :ghpull:`10182`.
Extra patches and updates will be needed to the :mod:`ipykernel` package for this feature to be available to other clients like jupyter Notebook, Lab, Nteract, Hydrogen...
The use of Jedi can is barely noticeable on recent enough machines, but can be feel on older ones, in cases were Jedi behavior need to be adjusted, the amount of time given to Jedi to compute type inference can be adjusted with c.IPCompleter.jedi_compute_type_timeout, with object whose type were not inferred will be shown as <unknown>. Jedi can also be completely deactivated by using the c.Completer.use_jedi=False option.
The old Completer.complete() API is waiting deprecation and should be replaced replaced by Completer.completions() in a near future. Feedback on the current state of the API and suggestions welcome.
Python 3 only codebase
One of the large challenges in IPython 6.0 has been the adoption of a pure Python 3 code base, which lead us to great length to upstream patches in pip, pypi and warehouse to make sure Python 2 system still upgrade to the latest compatible Python version compatible.
We remind our Python 2 users that IPython 5 is still compatible with Python 2.7, still maintained and get regular releases. Using pip 9+, upgrading IPython will automatically upgrade to the latest version compatible with your system.
Warning
If you are on a system using an older verison of pip on Python 2, pip may still install IPython 6.0 on your system, and IPython will refuse to start. You can fix this by ugrading pip, and reinstalling ipython, or forcing pip to install an earlier version: pip install 'ipython<6'
The ability to use only Python 3 on the code base of IPython has bring a number of advantage. Most of the newly written code make use of optional function type anotation leading to clearer code and better documentation.
The total size of the repository has also for a first time between releases (excluding the big split for 4.0) decreased by about 1500 lines, potentially quite a bit more codewide as some documents like this one are append only and are about 300 lines long.
The removal as of Python2/Python3 shim layer has made the code quite clearer and more idiomatic in a number of location, and much friendlier to work with and understand. We hope to further embrace Python 3 capability in the next release cycle and introduce more of the Python 3 only idioms (yield from, kwarg only, general unpacking) in the code base of IPython, and see if we can take advantage of these as well to improve user experience with better error messages and hints.
Miscs improvements
- The :cellmagic:`capture` magic can now capture the result of a cell (from an expression on the last line), as well as printed and displayed output. :ghpull:`9851`.
- Pressing Ctrl-Z in the terminal debugger now suspends IPython, as it already does in the main terminal prompt.
- autoreload can now reload Enum. See :ghissue:`10232` and :ghpull:`10316`
- IPython.display has gained a :any:`GeoJSON <IPython.display.GeoJSON>` object. :ghpull:`10288` and :ghpull:`10253`