Fernando Perez | 19 Nov 22:42 2015

[JOB] Project Jupyter is hiring two postdoctoral fellows <at> UC Berkeley.

Hi all,

We are delighted to announce today that Project Jupyter/IPython has two postdoctoral fellowships open at UC Berkeley, open immediately.  Interested candidates can apply here:


We hope to find candidates who will work on a number of challenging questions over the next few years, as described in our grant proposal here:

Interested candidates should carefully read that proposal before applying to familiarize themselves with the full scope of the questions we intend to tackle.

We'd like to thank the support of the Helmsley Trust, the Gordon and Betty Moore Foundation and the Alfred P. Sloan Foundation.


Brian Granger and Fernando Perez.

Fernando Perez ( <at> fperez_org; http://fperez.org)
fperez.net-at-gmail: mailing lists only (I ignore this when swamped!)
fernando.perez-at-berkeley: contact me here for any direct mail
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steffenl | 12 Oct 15:30 2015

Updating a FloatProgress widget within a thread doesn't work anymore in a notebook

I am writing a application that calculates some physical beheaviour based on
user defined models. These calculations have a high workload. Therefore the
user needs some information over the calculation progress. 
It is very difficult to show the progress in a Jupyter notebook. With text
printing the output can not easily get flushed because of the notebooks
output handling. Therefore I used the FloatProgress widget out of the
IPython.html module. I used a threading.Timer to update the widgets value.
This no longer works in the updated ipython version 3.2. 
The widget does not show the actual value. It updates its visual
representation only once after the code in the nodebook cell is already
How is it possible to update the visual representation of the widget during
the computation? The following simplified code can show the problem if it
runs in a notebook cell:

from IPython.html import widgets
from IPython.display import display
import threading

class Counter:
    """Simulates a task with heavy workload.
    The 'value' attribut holds the state of the progress.
    If the value of 'value' reaches the value of the 'max' attribut, 
    the work is done."""

    def __init__(self, max):
        self.max = max
        self.value = 0

    def count(self):
        for i in xrange(self.max + 1):
            for _ in xrange(self.max):
                self.value = i

class ProgressBar(widgets.FloatProgress):  

    def __init__(self, counter):
        super(ProgressBar, self).__init__()        
        self.max = counter.max
        self.counter = counter

    def show_progress(self):
        self._timer = (
                            function=self.show_progress)) # restart timer
        self._timer.daemon = True # kill thread at shut down of main process        
        self.value = self.counter.value # here, the bar should visually
        if self.value >= self.max:
            self.bar_style = 'success'            

c = Counter(10000)
s = ProgressBar(c)

View this message in context: http://python.6.x6.nabble.com/Updating-a-FloatProgress-widget-within-a-thread-doesn-t-work-anymore-in-a-notebook-tp5173902.html
Sent from the IPython - User mailing list archive at Nabble.com.
Omar Andrés Zapata Mesa | 3 Oct 05:47 2015

Running cling kernel

Hi dear ipython developers,
I am trying to run cling kernel but I am getting the next error,

WARNING:root:kernel 82b2aa8f-4df1-47f4-b0cc-fce628f19590 restarted
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/usr/local/lib/python2.7/dist-packages/clingkernel.py", line 18, in <module>
    from pexpect import replwrap, EOF
ImportError: cannot import name replwrap

I have a fresh install from github repo for ipython and I am using debian sid.

Best regards.
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Thomas Robitaille | 29 Sep 15:59 2015

ANN: numtraits v0.2

Hi everyone,

(apologies if you already saw this on the numpy-discussion list. I am
resending it to the scipy-user and ipython-user mailing lists since
these were down last week)

We have released a small experimental package called numtraits that
builds on top of the traitlets package and provides a NumericalTrait
class that can be used to validate properties such as:

* number of dimension (for arrays)
* shape (for arrays)
* domain (e.g. positive, negative, range of values)
* units (with support for astropy.units, pint, and quantities)

The idea is to be able to write a class like:

    class Sphere(HasTraits):

        radius = NumericalTrait(domain='strictly-positive', ndim=0)
        position = NumericalTrait(shape=(3,))

and all the validation will then be done automatically when the user
sets 'radius' or 'position'.

In addition, tuples and lists can get automatically converted to
arrays, and default values can be specified. You can read more about
the package and see examples of it in use here:


and it can be easily installed with

  pip install numtraits

The package supports both Python 3.3+ and Legacy Python (2.7) :)

At this point, we would be very interested in feedback - the package
is still very young and we can still change the API if needed. Please
open issues with suggestions!


Tom and Francesco
Vasco | 25 Sep 09:44 2015

%matplotlib qt hangs notebook

sometimes when I run %matplotlib qt in the ipython notebook (v4), it is 
indicated that the cell is executed and that the kernel is not busy. 
However, the next cell cannot be executed: there appears a *, as should 
be, but there is no output, the * remains, but the kernel does not look 

This mainly happens when I run the second cell, while the %matplotlib qt 
command is not finished yet.

Is this a known problem? How can I diagnose what is going on? I tried to 
start jupyter with --debug flag, but it does not give any errors or 
messages relating the notebook/kernel that is giving problems.

This problem occurs at both a windowsxp machine with the newest python3 
version from anaconda, as on a ubuntu machine, with
* python '3.4.0 (default, Jun 19 2015, 14:20:21) \n[GCC 4.8.2]'
* matplotlib 1.3.1

Both with ipython4 from pypi

Kind regards,
reckoner | 11 Sep 03:58 2015

Re: Connect to remote kernel on AWS using local qtconsole?

For reference, I posted some code and the solution to this problem here:


Pietro Terna | 3 Sep 23:09 2015


     Hi all,

     what's the substitute of the old magic %R? (I was easily connecting 
Python to R via that magic).

     Best, Pietro


The world is full of interesting problems to be solved!

Home page: http://web.econ.unito.it/terna
A new book on ABMs: http://www.palgrave.com/page/detail/agentbased-models-of-the-economy-/?K=9781137339805
SLAPP shell for ABMs: https://github.com/terna/SLAPP/
Aaron Watters | 27 Aug 15:05 2015

IPython widget Dict not syncing

I’m playing around with I-Python interactive widgets — very cool!

I’m having trouble passing dictionaries from the Python side to the JS side.
For some reason I can get a List to sync from the python side to the javascript side like so:

Py:    commands = List([], sync=True)

Js:  var commands = this.model.get("commands”);

But the same doesn’t seem to work with Dict

Py:      style = Dict({}, sync=True)

I’m pretty sure I’m using JSON compatible values and I’m changing the top level reference to get traitlets to notice that the value has changed.  I wouldn’t rule out that I’m doing something else dumb, however.

For fun I just changed the code to pass a dictionary wrapped in a list and it worked.  Any idea what is wrong?  Thanks!
  — Aaron Watters

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Reckoner | 24 Aug 22:30 2015

Connect to remote kernel on AWS using local qtconsole?


 By following the instructions listed here:

Running a notebook server — IPython 1.2.1: An Afternoon Hack documentation - https://ipython.org/ipython-doc/rel-1.1.0/interactive/public_server.html

I have been able to connect to a remote notebook server on Amazon AWS via the browser. Can I get to this kernel using   a local qtconsole?  In other words, can I do something like this on the local client:

% ipython qtconsole --kernel <something>

My concern is that the instructions listed above refer to a password and certificate that is required by the browser to connect to the remote server. How would this work with the desired qtconsole? Maybe some kind of tunnel is required to handle this case?

Thanks in advance.

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Akim Demaille | 24 Aug 15:05 2015

Compressed notebooks

Hi Guys,

First of all, congrats on the release!

However, it's hard to get information about this release.  The website is a little terse, and even
http://ipython.org/news.html stops at 3.2.

Is there some plans to add support for compressed notebooks?  I don't particularly thinks this is needed,
however, my package features documentation as notebooks installed in /usr/share/doc.  And debian tools
_love_ to compress about everything that is in /usr/share/doc. So I have to struggle with these tools to be
able to get readable documentation.

However, it is not particularly stupid either to compress these files, and I expect more packages will face
the same problem as I did.  So you might want to consider support for such notebooks?


FWIW, from https://www.debian.org/doc/debian-policy/ch-docs.html

> 12.3 Additional documentation
> Any additional documentation that comes with the package may be installed at the discretion of the
package maintainer. Plain text documentation should be installed in the directory
/usr/share/doc/package, where package is the name of the package, and compressed with gzip -9 unless it
is small.
Viktor Ransmayr | 23 Aug 22:35 2015

Fwd: IPython 4.0 on Python 3.4 & Windows 10 - Status Update #3

Please ignore this posting for the moment. - Thomas has helped me to resolve a major issue I had in my setup. - See http://mail.scipy.org/pipermail/ipython-user/2015-August/014008.html.

I'm planning to start with a 'clean/ fresh' installation, based on the current IPython 4.0/ JUpyter 1.0 documentation & report back to this list.

Thanks for all the support that you provided to me!

With kind regards,


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