Gustavo on Information Technology

Yes, I’m alive.

Since the second half of last summer I’ve been inactive in the Free Software arena. No commits, no emails from me in the last few months which may indicate that the projects are dead. So I wanted to write to let you know that I have no plans to stop maintaining any of my projects. I will start to catch up with all the things I’ve missed in the projects I normally contribute to and the projects I develop alone.

The reason why you’d heard nothing from me is that I left Spain to move to Oxford, in order to work at the cool company behind 2degreesnetwork.com. The removal was the most time-consuming and stressful thing I’d ever done, but after one month working here, I’m happy to say that it was worth it. The atmosphere is just like I thought Web 2.0 companies were, and I am surrounded by nice and talented people. I can’t be happier.

Well, back to the projects, I had to wait a lot to get access to the Internet at home, but I got it a couple of weeks ago and have been catching up (slowly) with the pending stuff. I still have a huge stack of unanswered emails, for example.

For the last couple of weeks I was working fulltime on repoze.what 1.1 and repoze.what-django. I hope to finish the documentation and get the first alpha releases out very soon; the code itself is pretty much ready and, as usual, fully tested. I didn’t have plans to do a repoze.what 1.1 release anytime soon, but while developing repoze.what-django I found myself implementing something which would be useful outside Django (i.e., ACLs) and thus I decided to move it to repoze.what.

After that, I want to improve the auth documentation in TurboGears 2. repoze.what-pylons is the crucial part of the repoze.what integration in TG2 and it’s fully documented, but duplicating part of those docs won’t do any harm and adding some tips and tricks would be nice. I started doing that some months ago but never committed it; I have to finish it this time.

Then I’d like to make repoze.what-pylons take advantage of the new features in repoze.what 1.1, like repoze.what-django already does.

That’s it for the foreseeable future. Next year I really want to get serious with Booleano and PyACL.

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I recently had to implement a recommender system for the Netflix Prize. Out of the best known models, I chose Yehuda Koren’s SVD++ model as published on the paper entitled “Factorization Meets the Neighborhood: a Multifaceted Collaborative Filtering Model” (the version that doesn’t take into account temporal effects; I’d have implemented the complete model, but couldn’t due to time constraints).

I named this Python-based project “wooflix” and you can download it from code.gustavonarea.net. It ships with a command-line interface and basic documentation, including the design document.

It’s the first project, as far as I know, that uses Booleano. With it, you can get random movie recommendations and filter them, like this:

# Get 5 movie recommendations for user #7, at least those published after 2001
wooflix recommendations 7 --max="5" --filter="movie:year > 2001"

Keep in mind that I won’t offer support for it; I’m publishing because I thought it might be useful for some people, but I have no intentions to work on it in the future.

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I am proud to announce the first alpha release of Booleano, a Python-based interpreter of boolean expressions:

Booleano is an interpreter of boolean expressions, a library to define and run filters available as text (e.g., in a natural language) or in Python code.

In order to handle text-based filters, Booleano ships with a fully-featured parser whose grammar is adaptive: Its properties can be overridden using simple configuration directives.

On the other hand, the library exposes a pythonic API for filters written in pure Python. These filters are particularly useful to build reusable conditions from objects provided by a third party library.

It’s been designed to address the following use cases:

1. Convert text-based conditions: When you need to turn a condition available as plain text into something else (i.e., another filter).
2. Evaluate text-based conditions: When you have a condition available as plain text and need to iterate over items in order to filter out those for which the evaluation of the condition is not successful.
3. Evaluate Python-based conditions: When you have a condition represented by a Python object (nothing to be parsed) and need to iterate over items in order to filter out those for which the evaluation of the condition is not successful.

It is a project I found necessary while working on repoze.what 2, which I’ve been developing for the last few months in my spare time. This release is absolutely usable, but lacks documentation because I needed this release out for a (small) project I need to work on ASAP (it will depend on Booleano). The next release will ship with a nice documentation, I promise.

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My laptop was slow while running my chain and ball KDE 4, and also got some things broken recently (e.g., battery, screen hinges), so I decided to buy a new one last week before it leaves me stranded. And soon enough I realized that I had two options:

• Buy it in a place where every single computer ships with Windows, so that I could claim a refund. I didn’t care about the money: I just wanted to mess with that kind of vendors and file a lawsuit if I didn’t get it on good terms, to encourage people to do the same thing and thus contribute to do away with the Windows Tax.
• Purchase it from a Linux pre-installed vendor, to support them. Even if they pre-installed a freedom-trampling system like Windows, it’d be good to show them that Freedomware worths it.

I liked both options alike, so I based my decision on the computer specs and costs, not on the vendor/manufacturer.

I decided to get a Dell XPS M1330, one of the two Ubuntu-powered computers that I remembered Dell sells in Spain. So I visited dell.es/ubuntu and was surprised to find just a couple of netbooks! Change of plans; now I’ll have to get it with Windows and claim a refund, I told myself.

So the first step was to get a proof that I was imposed the operating system when I bought the laptop. Sales representatives were available for a chat, so I asked them how could I get a Dell XPS M1330 without Windows. The surprising answer was that it was available with Ubuntu and pointed me to configure2.euro.dell.com/dellstore/! Plans changed one more time; back to the original plan, get it with Linux.

I obviously asked why it wasn’t listed on dell.es/ubuntu. The sales rep said that s/he didn’t know why and that s/he will forward my query to the relevant department. I bought the laptop with Ubuntu that day and that was it.

Today, out of curiosity, I went to dell.es/ubuntu and found that it hasn’t changed! The link the sales rep provided me with the other day still works but the laptop is not listed. And the same happens in dell.fr/ubuntu, dell.co.uk/ubuntu and dell.de/ubuntu, for example.

This can hardly be a mistake. Why the heck does Dell hide some of the few Linux-powered computers they sell now? Maybe due to threats from Microsoft? After all, it’s well-know for its monopolistic practices.

PS (April 18th @ 14:00 UTC): The link above to configure2.euro.dell.com/dellstore/ doesn’t work at times today, so here’s an screenshot if it doesn’t work for you:

PS (April 19th @ 18:30 UTC): This is an screenshot of the random error I warned about yesterday (which I took just in case), before reaching Digg.com’s front-page:

Now, almost 20 hours after reaching Digg’s front-page, the link no longer works (not even at times, as yesterday) and a better formatted page is displayed instead:

I don’t know if the different error pages actually mean something, but my point is that the link is now dead.

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Some weeks ago I was invited to make repoze.who.plugins.ldap an official repoze.who plugin, which means that:

• The license will change. It will use Repoze’s.
• The development tools will be migrated from Launchpad (bug tracker, repository, etc).
• The LDAP plugin’s documentation will be included into repoze.who’s.
• It will be maintained by Repoze commiters, and I’m one of them.

I’ve not started the migration, but I hope to start in a few days.

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repoze.who.plugins.ldap is an straightforward yet powerful solution to enable LDAP authentication in your WSGI application. It enables you to have LDAP authentication working in your new or existing applications, in few minutes and with few lines of code!

It’s a plugin for the repoze.who framework, featuring not only an LDAP authenticator, but also related utilities. It’s a fully documented project which also ships with a working demo application, so it’d be hard for you to get stuck.

I wrote this plugin in order to enable LDAP authentication in Animador. And in fact, it’s the first application that uses the plugin.

The latest version is 1.0, and you’re highly encouraged to play with it and give feedback!

Visit its website for more information!

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I’ve had the great pleasure of being invited by the TurboGears team to become an official committer for the great TurboGears framework.

This is because I’ve been contributing patches for TurboGears 2 and other packages used by Animador (a TurboGears 2 application), since I started its development, in order to fix bugs and/or add new features that I want in Animador. So now I can apply my changes by myself!

And stay tunned, because very soon it’s going to be very easy to add OpenId support to any WSGI application by means of a plugin for the framework-independent repoze.who package!

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