The more we use mercurial to manager our code repositories, the more we enjoy its extended functionalities. Lately we've been playing and using branches which end up being very useful. We also use hgview instead of the built-in "hg view" command. And it's latest release supports the branches functionality, you can filter out the branch you want to look at. Update your installation (apt-get upgrade ?) to enjoy this new functionality... or download it.

On distutils-sig, the question of distutils/setuptools replacing is frequently raised and a lot of effort is made to find what would be the more occurate way to build and distribute python code.

I don't understand the reason why we have a massive coupling between build and distribution (setuptools and pypi to be more precise) and I'm not convinced about this "global" approach. I hope the python community will examine the possibility to change that and split the problem in two separated projects.

One of the most successful idea of Python is its power in extending other languages. And in fact, that's the major problem to solve for the build area. I'm pretty sure it will take a long time before obtaining a valuable (and adopted) solution and this is so complicated that the choice of the building chain should be kept under the responsibility of the upstream maintainers for now (distutils, setuptools, makefile, SCons, ...).

Concerning the distribution, here are the mandatory features I expect:

• installing source code managing dependencies with foreign contribution
• have binary builds without interact with the primary host system
• be multi-platform agnostic (Linux, BSD, Windows, Mac, ...)
• clean upgrade/uninstall
• kind of sandboxes for testing and development mode
• no administrator privilege required

I found the http://0install.net project homepage and was really impressed by the tons of functionalities already available and the other numerous advantages, like:

• multiple version installation
• reuse external distribution effort (integrate deb, rpm, ...)
• digital signatures
• basic mirroring solution
• notification about software updates
• command line oriented but various GUI exist
• try to follow standards (XDG specifications on freedesktop.org))

I'm questioning seriously why this project could not be considered as a clean and build-independent python packages index system. Moreover, 0install has already some build capabilities (see 0compile) but the ultime reason is that it will largely facilitate migrations when a new python build standard will emerge.

My latest personal project, pygpibtoolkit, holds a simple HPGL plotter trying to emulate the HP7470A GPIB plotter, using the very nice and cheap Prologix USB-GPIB dongle. This tool is (for now) called qgpibplotter (since it is using the Qt4 toolkit).

Tonight, I took (at last) the time to make it work nicely. Well, nicely with the only device I own which is capable of plotting on the GPIB bus, my HP3562A DSA.

Now, you just have to press the "Plot" button of your test equipment, and bingo! you can see the plot on your computer.

I've been using for a long time a custom version of gajim in order to make it interact with wmii. More precisely, I have, in my wmii status bar, a dedicated log zone where I print notification messages such as new incoming emails or text received from gajim (with different colors if special words were cited, etc.).

I recently decided to throw away my custom gajim and use python and dbus to achieve the same goal in a cleaner way. A very basic version can be found in the simpled project. As of now, the only way to get the code is trhough mercurial:

hg clone http://www.logilab.org/hg/simpled

The source file is named gajimnotifier.py. In this file, you'll also find a version sending messages to Ion's status bar.

Graphical user interfaces help command discovery, while command-line interfaces help command efficiency. This article tries to explain why. I reached it when reading the list of references from the introduction to Ubiquity, which is the best extension to firefox I have seen so far. I expect to start writing Ubiquity commands soon, since I have already been using extensively the 'keyword shorcut' functionnality of firefox's bookmarks and we have already done work in the area of 'language interaction', as they call it at Mozilla Labs, when working with Narval. Our Logilab Simple Desktop project, aka simpled, also goes in the same direction since it tries to unify different applications into a coherent work environment by defining basic commands and shorcuts that can be applied everywhere and accessing the rest of the functionnalities via a command-line interface.

The Openmoko Freerunner is a computer with embedded GSM, accelerometer and GPS. I got mine last week after waiting for a month for the batch to get from Taiwan to the french company I bought it from. The first thing I had to admit was that some time will pass before it gets confortable to use it as a phone. The current version of the system has many weird things in its user interface and the phone works, but the other end of the call suffers a very unpleasant echo.

I will try to install Debian, Qtopia and Om2008.8 to compare them. I also want to quickly get Python scripts to run on it and get back to Narval hacking. I had an agent running on a bulky Palm+GPS+radionetwork back in 1999 and I look forward to run on this device the same kind of funny things I was doing in AI research ten years ago.

I bought last week a new laptop computer that can drive a 24" LCD monitor, which means I do not need my desktop computer any more. In the process of setting up that new laptop, I did what I have been wanting to do for years without finding the time: spending time on my ion3 config to make it more generic and create a small python setup utility that can regenerate it from a template file and a keyboard layout.

The simpled project was born!

If you take a look at the list of pending tickets, you will guess that I am using a limited number of pieces of software during my work day and tried to configure them so that they share common action/shortcuts. This is what simpled is about: given a keyboard layout generate the config files for the common tools so that action/shortcuts are always on the same key.

I use ion3, xterm+bash, emacs, mutt, firefox, gajim. Common actions are: open, save, close, move up/down/left/right, new frame or tab, close frame or tab, move to previous or next tab, etc.

I will give news in this blog from time to time and announce it on mailing lists when version 0.1 will be out. If you want to give it a try, get the code from the mercurial repository.

While working on knowledge management and semantic web technologies, I came across the Simile project at MIT a few years back. I even had a demo of the Exhibit widget fetching then displaying data from our semantic web application framework back in 2006 at the Web2 track of Solutions Linux in Paris.

Now that we are using these widgets when implementing web apps for clients, I was happy to see that the projects got a life of their own outside of MIT and became full-fledged free-software projects hosted on Google Code. See Simile-Widgets for more details and expect us to provide a debian package soon unless someone does it first.

Speaking of Debian, here is a nice demo a the Timeline widget presenting the Debian history.

We have been using many different tools for doing statistical analysis with Python, including R, SciPy, specific C++ code, etc. It looks like the growing audience of SciPy is now in movement to have dedicated modules in SciPy (lets call them SciKits). See this thread in SciPy-user mailing-list.

A Google custom search engine for Python has been made available by Gerard Flanagan, indexing:

• The Hazel Tree
• The Python standard library docs
• The Python wiki
• Python Package Index

The presentation of Python as a tool for applied mathematics got highlighted at the 2008 annual meeting of the american Society for Industrial and Applied Mathematics (SIAM). For more information, read this blogpost and the slides.

Un problème rencontré hier : un test unitaire plante sous Windows, après avoir créé un objet qui garde des fichiers ouverts. le tearDown du test est appelé, mais il plante car Windows refuse de supprimer des fichiers ouverts, et le framework de test garde une référence sur la fonction de test pour qu'on puisse examiner la pile d'appels. Sous Linux, pas de problème (on a le droit du supprimer du disque un fichier ouvert, et donc pas de soucis dans le teardown).

Quelques pistes pour contourner le problème:

1. mettre le test dans un try...finally avec un del sur l'objet qui garde les fichiers ouverts dans le finally. Inconvénient : quand le test ne passe pas, pdb ne permet plus de voir grand chose
2. au lieu de nettoyer dans le tearDown, nettoyer plus tard dans un atexit par exemple. Il faut voir comment ça se passe si plusieurs tests veulent écrire dans les mêmes fichiers (je pense qu'il faudrait un répertoire temporaire par test, si on veut pouvoir avoir plusieurs tests qui foirent et examiner leurs données, mais il faut tester pour être sûr)
3. coller un try...except dans le tearDown autour de la suppression de chaque fichier, et mettre les fichiers qui posent problème dans une liste qui sera traitée à la sortie du programme (avec atexit par exemple).

Ça ressemble à du bricolage, mais on a un comportement de windows sur lequel on n'a pas de contrôle (même avec des privilèges Administrateur ou System, on ne peut pas contourner cette impossibilité de supprimer un fichier ouvert, à ma connaissance).

Une autre approche, nettement plus lourde, serait de virtualiser la création de fichiers pour travailler en mémoire (au minimum surcharger os.mkdir et le builtin open, voire dans le cas qui nous intéresse les modules qui travaillent avec des fichiers zip). Il y a peut-être des choses comme ça en circulation. Poser la question sur la liste TIP apportera peut-être des réponses (une rapide recherche dans les archives n'a rien donné).

Voir aussi ces enfilades de mars 2004 et novembre 2004 sur comp.lang.python.

I have a laptop I use at work (with a docking station), in the train and at home (with an external display), on which my environment is ion3.

As I use suspend-to-RAM all the time, I have added some keybindings to automatically reconfigure my screen when I plug/unplug an external display (on the dock as well as direct VGA connection).

The lua code to paste in your .ion3/cfg_ion.lua for the bindings looks like:

function autoscreen_on()
        local f = io.popen('/home/david/bin/autoscreen -c', 'r')
      if not f then
          return
      end
      local s = f:read('*a')
      f:close()
    ioncore.restart()
end

function autoscreen_off()
        local f = io.popen('/home/david/bin/autoscreen -d', 'r')
      if not f then
          return
      end
      local s = f:read('*a')
      f:close()
    ioncore.restart()
end

defbindings("WMPlex.toplevel", {
    bdoc("Turn on any external display and tell ion to reconfigure itself"),
    kpress(META.."F10",
           "autoscreen_on()"),
})

defbindings("WMPlex.toplevel", {
    bdoc("Turn off any external display and tell ion to reconfigure itself"),
    kpress(META.."F11",
           "autoscreen_off()"),
})

It makes use of the following python script (named /home/david/bin/autoscreen in the lua code above):

#!/usr/bin/env python

import sys
import os
import re
from subprocess import Popen, PIPE
import optparse
parser = optparse.OptionParser("A simple automatic screen configurator (using xrandr)")
parser.add_option('-c', '--connect', action="store_true",
                  dest='connect',
                  default=False,
                  help="configure every connected screens")
parser.add_option('-d', '--disconnect', action="store_true",
                  dest='disconnect',
                  default=False,
                  help="unconfigure every connected screens other than LVDS (laptop screen)")
parser.add_option('', '--main-display',
                  dest='maindisplay',
                  default="LVDS",
                  help="main display identifier (typically, the laptop LCD screen; defaults to LVDS)")

options, args = parser.parse_args()

if int(options.connect) + int(options.disconnect) > 1:
    print "ERROR: only one option -c or -d at a time"
    parser.print_help()
    sys.exit(1)


xrandr = Popen("xrandr", shell=True, bufsize=0, stdout=PIPE).stdout.read()

connected = re.findall(r'([a-zA-Z0-9-]*) connected', xrandr)
connected = [c for c in connected if c != options.maindisplay]

cmd = "xrandr --output %s %s"

if options.connect or options.disconnect:
    for c in connected:
        if options.connect:
            action = "--auto"
        elif options.disconnect:
            action = "--off"

        p = Popen(cmd % (c, action), shell=True)
        sts = os.waitpid(p.pid, 0)

Hey,

We've decided to go to Europython this year. We're obviously going to give a talk about the exciting things we're doing with LAX and GoogleAppEngine. We're on wednesday at midday in the alfa room, check out the schedule here. Since we think it's important that these events take place, we're also chipping in and sponsoring the event.

We hope to see you there. Drop us a note if you want to meet up.