Blog entries

  • Interesting things seen at the Afpy Computer Camp

    2011/11/28 by Pierre-Yves David

    This summer I spent three days in Burgundy at the Afpy Computer Camps. This yearly meeting gathered French speaking python developers for talking and coding. The main points of this 2011 edition were:

    The new IPython 0.11 was shown by Olivier Grisel. This new version contains lots of impressive feature like inline figures, asynchronous execution, exportable sessions, and a web-browser based client. IPython was also presented by its main author Fernando Perez during his keynote talk at EuroSciPy. Since then Logilab got involved with IPython. We contributed to the Debian packaging of iPython dependencies and we joined the discussion about Restructured Text formatting for note book.

    Tarek Ziade bootstrapped his new Red Barrel project and small framework to build modern webservices with multiple back-end including the new protocol.

    Alexis Métaireau and Feth Arezki discovered their common interest into account tracking application. The discussion's result is a first release of I hate money a few months later.

    For my part, I spent most of my time working with Boris Feld on the Python Testing Infrastructure , a continuous integration tool to test python distributions available at PyPI.

    This yearly Afpy Computer Camps is an event intended for python developers but the Afpy also organize events for non python developer. The next one is tonight in Paris at La cantine : Vous reprendrez bien un peu de python ?. See you tonight ?

  • A Python dev day at La Cantine. Would like to have more PyCon?

    2012/06/01 by Damien Garaud

    We were at La Cantine on May 21th 2012 in Paris for the " Replay session".

    La Cantine is a coworking space where hackers, artists, students and so on can meet and work. It also organises some meetings and conferences about digital culture, computer science, ...

    On May 21th 2012, it was a dev day about Python. "Would you like to have more PyCon?" is a french wordplay where PyCon sounds like Picon, a french "apéritif" which traditionally accompanies beer. A good thing because the meeting began at 6:30 PM! Presentations and demonstrations were about some Python projects presented at PyCon 2012 in Santa Clara (California) last March. The original pycon presentations are accessible on

    PDB Introduction

    By Gael Pasgrimaud (@gawel_).

    pdb is the well-known Python debugger. Gael showed us how to easily use this almost-mandatory tool when you develop in Python. As with the gdb debugger, you can stop the execution at a breakpoint, walk up the stack, print the value of local variables or modify temporarily some local variables.

    The best way to define a breakpoint in your source code, it's to write:

    import pdb; pdb.set_trace()

    Insert that where you would like pdb to stop. Then, you can step trough the code with s, c or n commands. See help for more information. Following, the help command in pdb command-line interpreter:

    (Pdb) help
    Documented commands (type help <topic>):
    EOF    bt         cont      enable  jump  pp       run      unt
    a      c          continue  exit    l     q        s        until
    alias  cl         d         h       list  quit     step     up
    args   clear      debug     help    n     r        tbreak   w
    b      commands   disable   ignore  next  restart  u        whatis
    break  condition  down      j       p     return   unalias  where
    Miscellaneous help topics:
    exec  pdb

    It is also possible to invoke the module pdb when you run a Python script such as:

    $> python -m pdb


    By Alexis Metereau (@ametaireau).

    Pyramid is an open source Python web framework from Pylons Project. It concentrates on providing fast, high-quality solutions to the fundamental problems of creating a web application:

    • the mapping of URLs to code ;
    • templating ;
    • security and serving static assets.

    The framework allows to choose different approaches according the simplicity//feature tradeoff that the programmer need. Alexis, from the French team of Services Mozilla, is working with it on a daily basis and seemed happy to use it. He told us that he uses Pyramid more as web Python library than a web framework.


    By Benoit Chesneau (@benoitc).

    Circus is a process watcher and runner. Python scripts, via an API, or command-line interface can be used to manage and monitor multiple processes.

    A very useful web application, called circushttpd, provides a way to monitor and manage Circus through the web. Circus uses zeromq, a well-known tool used at Logilab.

    matplotlib demo

    This session was a well prepared and funny live demonstration by Julien Tayon of matplotlib, the Python 2D plotting library . He showed us some quick and easy stuff.

    For instance, how to plot a sinus with a few code lines with matplotlib and NumPy:

    import numpy as np
    import matplotlib.pyplot as plt
    fig = plt.figure()
    ax = fig.add_subplot(111)
    # A simple sinus.
    ax.plot(np.sin(np.arange(-10., 10., 0.05)))

    which gives:

    You can make some fancier plots such as:

    # A sinus and a fancy Cardioid.
    a = np.arange(-5., 5., 0.1)
    ax_sin = fig.add_subplot(211)
    ax_sin.plot(np.sin(a), '^-r', lw=1.5)
    ax_sin.set_title("A sinus")
    # Cardioid.
    ax_cardio = fig.add_subplot(212)
    x = 0.5 * (2. * np.cos(a) - np.cos(2 * a))
    y = 0.5 * (2. * np.sin(a) - np.sin(2 * a))
    ax_cardio.plot(x, y, '-og')
    ax_cardio.set_xlabel(r"$\frac{1}{2} (2 \cos{t} - \cos{2t})$", fontsize=16)

    where you can type some LaTeX equations as X label for instance.

    The force of this plotting library is the gallery of several examples with piece of code. See the matplotlib gallery.

    Using Python for robotics

    Dimitri Merejkowsky reviewed how Python can be used to control and program Aldebaran's humanoid robot NAO.

    Wrap up

    Unfortunately, Olivier Grisel who was supposed to make three interesting presentations was not there. He was supposed to present :

    • A demo about injecting arbitrary code and monitoring Python process with Pyrasite.
    • Another demo about Interactive Data analysis with Pandas and the new IPython NoteBook.
    • Wrap up : Distributed computation on cluster related project: IPython.parallel, picloud and Storm + Umbrella

    Thanks to La Cantine and the different organisers for this friendly dev day.

  • Second Salt Meetup builds the french community

    2014/03/04 by Arthur Lutz

    On the 6th of February, the Salt community in France met in Paris to discuss Salt and choose the tools to federate itself. The meetup was kindly hosted by IRILL.

    There were two formal presentations :

    • Logilab did a short introduction of Salt,
    • Majerti presented a feedback of their experience with Salt in various professional contexts.

    The presentation space was then opened to other participants and Boris Feld did a short presentation of how Salt was used at NovaPost.

    We then had a short break to share some pizza (sponsored by Logilab).

    After the break, we had some open discussion about various subjects, including "best practices" in Salt and some specific use cases. Regis Leroy talked about the states that Makina Corpus has been publishing on github. The idea of reconciling the documentation and the monitoring of an infrastructure was brought up by Logilab, that calls it "Test Driven Infrastructure".

    The tools we collectively chose to form the community were the following :

    • a mailing-list kindly hosted by the AFPY (a pythonic french organization)
    • a dedicated #salt-fr IRC channel on freenode

    We decided that the meetup would take place every two months, hence the third one will be in April. There is already some discussion about organizing events to tell as many people as possible about Salt. It will probably start with an event at NUMA in March.

    After the meetup was officially over, a few people went on to have some drinks nearby. Thank you all for coming and your participation.

    login or register to comment on this blog

  • PyconFR 2014 - on y va !

    2014/10/24 by Arthur Lutz est l’événement annuel qui rassemble les utilisateurs et développeurs Python en France, c'est une conférence organisée par l'AFPY (L'Association Francophone Python). Elle se déroulera cette année sur 4 jours à Lyon : 2 jours de conférences, 2 jours de sprints.

    Nous serons présents à PyconFR les samedi et dimanche pour y voir les présentation nombreuses et prometteuses. Nous assisterons en particulier à deux présentations qui sont liés à l'activité de Logilab :

    On espère vous y croiser. Si tout va bien, nous prendrons le temps de faire un compte rendu de ce qui a retenu notre attention lors de la conférence.