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`

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.

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`.

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`

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).

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}',
...
}

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.

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.

# notebook

from mymodule import MyClass
first = MyClass(5)

# 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.