Cajón de escritorio: recortes y cosas útiles

Repairing PostgreSQL after upgrading to Mac OSX Lion

2012-02-07T18:58:00.000-03:00

I upgraded to Mac OSX to 10.7.3 (Lion) yesterday and had some issues with PostgreSQL.

For instance, when I tried to run the South migrations for the Django project I'm working at, I got this:

psycopg2.OperationalError: could not connect to server: Permission denied
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?

How I fixed this?

Edit PostgreSQL's config to define the unix_socket_directory setting:

$ sudo nano /Library/PostgreSQL/9.0/data/postgresql.conf

In my case I changed the setting to unix_socket_directory = '/var/pgsql_socket/'.

Exceute the following commands:

$ sudo dscl . append /Groups/_postgres GroupMembership postgres
$ sudo chmod g+w,o+rx /var/pgsql_socket/

Restart the server:

$ sudo -u postgres /Library/PostgreSQL/9.0/bin/pg_ctl -D /Library/PostgreSQL/9.0/data/ restart

Note: You may want to add an alias for this command in your ~/.profile file. If so, it is just a matter of adding a line like this:

alias restart_postgres='sudo -u postgres /Library/PostgreSQL/9.0/bin/pg_ctl -D /Library/PostgreSQL/9.0/data/ restart'

El Arjonio

2011-12-13T12:39:00.001-03:00

Excelente post de El Espíritu de los Cínicos: Link.

Después de que Dani Granatta inventara al Arjonio como forma de justificar de todos los males (poéticos), fue inevitable dejar constancia académica de su existencia.

A successful Git branching model

2011-11-10T09:34:00.003-03:00

Both at work and for my personal software-development-related projects I've been using this excellent branching model suggested by Vincent Driessen in his website: http://nvie.com/posts/a-successful-git-branching-model/

Here's an echo of his awesome post:

A successful Git branching model

Published: January 05, 2010

In this post I present the development model that I’ve introduced for all of myprojects (both at work and private) about a year ago, and which has turned outto be very successful. I’ve been meaning to write about it for a while now, butI’ve never really found the time to do so thoroughly, until now. I won’t talkabout any of the projects’ details, merely about the branching strategy andrelease management.

It focuses around Git as the tool for the versioning ofall of our source code.

Why git?

For a thorough discussion on the pros and cons of Git compared to centralizedsource code control systems, see the web. There are plenty of flame warsgoing on there. As a developer, I prefer Git above all other tools aroundtoday. Git really changed the way developers think of merging and branching.From the classic CVS/Subversion world I came from, merging/branching has alwaysbeen considered a bit scary (“beware of merge conflicts, they bite you!”) andsomething you only do every once in a while.
But with Git, these actions are extremely cheap and simple, and they areconsidered one of the core parts of your daily workflow, really. For example,in CVS/Subversion books, branching and merging isfirst discussed in the later chapters (for advanced users), while inevery Git book, it’s already covered in chapter 3(basics).
As a consequence of its simplicity and repetitive nature, branching and mergingare no longer something to be afraid of. Version control tools are supposed toassist in branching/merging more than anything else.
Enough about the tools, let’s head onto the development model. The model thatI’m going to present here is essentially no more than a set of procedures thatevery team member has to follow in order to come to a managed softwaredevelopment process.

Decentralized but centralized

The repository setup that we use and that works well with this branching model,is that with a central “truth” repo. Note that this repo is only consideredto be the central one (since Git is a DVCS, there is no such thing as a centralrepo at a technical level). We will refer to this repo as origin, since thisname is familiar to all Git users.

Each developer pulls and pushes to origin. But besides the centralizedpush-pull relationships, each developer may also pull changes from other peersto form sub teams. For example, this might be useful to work together with twoor more developers on a big new feature, before pushing the work in progress toorigin prematurely. In the figure above, there are subteams of Alice and Bob,Alice and David, and Clair and David.
Technically, this means nothing more than that Alice has defined a Git remote,named bob, pointing to Bob’s repository, and vice versa.

The main branches

At the core, the development model is greatly inspired by existing models outthere. The central repo holds two main branches with an infinite lifetime:

master
develop

The master branch at origin should be familiar to every Git user. Parallelto the master branch, another branch exists called develop.
We consider origin/master to be the main branch where the source code ofHEAD always reflects a production-ready state.
We consider origin/develop to be the main branch where the source code ofHEAD always reflects a state with the latest delivered development changesfor the next release. Some would call this the “integration branch”. This iswhere any automatic nightly builds are built from.
When the source code in the develop branch reaches a stable point and isready to be released, all of the changes should be merged back into mastersomehow and then tagged with a release number. How this is done in detail willbe discussed further on.
Therefore, each time when changes are merged back into master, this is a newproduction release by definition. We tend to be very strict at this, so thattheoretically, we could use a Git hook script to automatically build androll-out our software to our production servers everytime there was a commit onmaster.

Supporting branches

Next to the main branches master and develop, our development model uses avariety of supporting branches to aid parallel development between teammembers, ease tracking of features, prepare for production releases and toassist in quickly fixing live production problems. Unlike the main branches,these branches always have a limited life time, since they will be removedeventually.
The different types of branches we may use are:

Feature branches
Release branches
Hotfix branches

Each of these branches have a specific purpose and are bound to strict rules asto which branches may be their originating branch and which branches must betheir merge targets. We will walk through them in a minute.
By no means are these branches “special” from a technical perspective. Thebranch types are categorized by how we use them. They are of course plain oldGit branches.

Feature branches

May branch off from: develop
Must merge back into: develop
Branch naming convention: anything except master, develop, release-*,or hotfix-*
Feature branches (or sometimes called topic branches) are used to develop newfeatures for the upcoming or a distant future release. When startingdevelopment of a feature, the target release in which this feature will beincorporated may well be unknown at that point. The essence of a feature branchis that it exists as long as the feature is in development, but will eventuallybe merged back into develop (to definitely add the new feature to theupcoming release) or discarded (in case of a disappointing experiment).
Feature branches typically exist in developer repos only, not in origin.

Creating a feature branch

When starting work on a new feature, branch off from the develop branch.

$ git checkout -b myfeature develop
Switched to a new branch "myfeature"

Incorporating a finished feature on develop

Finished features may be merged into the develop branch definitely add themto the upcoming release:

$ git checkout develop
Switched to branch 'develop'
$ git merge --no-ff myfeature
Updating ea1b82a..05e9557
(Summary of changes)
$ git branch -d myfeature
Deleted branch myfeature (was 05e9557).
$ git push origin develop

The --no-ff flag causes the merge to always create a new commit object, evenif the merge could be performed with a fast-forward. This avoids losinginformation about the historical existence of a feature branch and groupstogether all commits that together added the feature. Compare:

In the latter case, it is impossible to see from the Git history which of thecommit objects together have implemented a feature—you would have to manuallyread all the log messages. Reverting a whole feature (i.e. a group of commits),is a true headache in the latter situation, whereas it is easily done if the--no-ff flag was used.
Yes, it will create a few more (empty) commit objects, but the gain is muchbigger that that cost.
Unfortunately, I have not found a way to make --no-ff the default behaviourof git merge yet, but it really should be.

Release branches

May branch off from: develop
Must merge back into: develop and master
Branch naming convention: release-*
Release branches support preparation of a new production release. They allowfor last-minute dotting of i’s and crossing t’s. Furthermore, they allow forminor bug fixes and preparing meta-data for a release (version number, builddates, etc.). By doing all of this work on a release branch, the developbranch is cleared to receive features for the next big release.
The key moment to branch off a new release branch from develop is whendevelop (almost) reflects the desired state of the new release. At least allfeatures that are targeted for the release-to-be-built must be merged in todevelop at this point in time. All features targeted at future releases maynot—they must wait until after the release branch is branched off.
It is exactly at the start of a release branch that the upcoming release getsassigned a version number—not any earlier. Up until that moment, the developbranch reflected changes for the “next release”, but it is unclear whether that“next release” will eventually become 0.3 or 1.0, until the release branch isstarted. That decision is made on the start of the release branch and iscarried out by the project’s rules on version number bumping.

Creating a release branch

Release branches are created from the develop branch. For example, sayversion 1.1.5 is the current production release and we have a big releasecoming up. The state of develop is ready for the “next release” and we havedecided that this will become version 1.2 (rather than 1.1.6 or 2.0). So webranch off and give the release branch a name reflecting the new versionnumber:

$ git checkout -b release-1.2 develop
Switched to a new branch "release-1.2"
$ ./bump-version.sh 1.2
Files modified successfully, version bumped to 1.2.
$ git commit -a -m "Bumped version number to 1.2"
[release-1.2 74d9424] Bumped version number to 1.2
1 files changed, 1 insertions(+), 1 deletions(-)

After creating a new branch and switching to it, we bump the version number.Here, bump-version.sh is a fictional shell script that changes some filesin the working copy to reflect the new version. (This can of course be a manualchange—the point being that some files change.) Then, the bumped versionnumber is committed.
This new branch may exist there for a while, until the release may be rolledout definitely. During that time, bug fixes may be applied in this branch(rather than on the develop branch). Adding large new features here isstrictly prohibited. They must be merged into develop, and therefore, waitfor the next big release.

Finishing a release branch

When the state of the release branch is ready to become a real release, someactions need to be carried out. First, the release branch is merged intomaster (since every commit on master is a new release by definition,remember). Next, that commit on master must be tagged for easy futurereference to this historical version. Finally, the changes made on the releasebranch need to be merged back into develop, so that future releases alsocontain these bug fixes.
The first two steps in Git:

$ git checkout master
Switched to branch 'master'
$ git merge --no-ff release-1.2
Merge made by recursive.
(Summary of changes)
$ git tag -a 1.2

The release is now done, and tagged for future reference.
Edit: You might as well want to use the -s or -u flags to signyour tag cryptographically.
To keep the changes made in the release branch, we need to merge those backinto develop, though. In Git:

$ git checkout develop
Switched to branch 'develop'
$ git merge --no-ff release-1.2
Merge made by recursive.
(Summary of changes)

This step may well lead to a merge conflict (probably even, since we havechanged the version number). If so, fix it and commit.
Now we are really done and the release branch may be removed, since we don’tneed it anymore:

$ git branch -d release-1.2
Deleted branch release-1.2 (was ff452fe).

Hotfix branches

May branch off from: master
Must merge back into: develop and master
Branch naming convention: hotfix-*
Hotfix branches are very much like release branches in that they are also meantto prepare for a new production release, albeit unplanned. They arise from thenecessity to act immediately upon an undesired state of a live productionversion. When a critical bug in a production version must be resolvedimmediately, a hotfix branch may be branched off from the corresponding tag onthe master branch that marks the production version.
The essence is that work of team members (on the develop branch) cancontinue, while another person is preparing a quick production fix.

Creating the hotfix branch

Hotfix branches are created from the master branch. For example, sayversion 1.2 is the current production release running live and causing troublesdue to a severe bug. But changes on develop are yet unstable. We may thenbranch off a hotfix branch and start fixing the problem:

$ git checkout -b hotfix-1.2.1 master
Switched to a new branch "hotfix-1.2.1"
$ ./bump-version.sh 1.2.1
Files modified successfully, version bumped to 1.2.1.
$ git commit -a -m "Bumped version number to 1.2.1"
[hotfix-1.2.1 41e61bb] Bumped version number to 1.2.1
1 files changed, 1 insertions(+), 1 deletions(-)

Don’t forget to bump the version number after branching off!
Then, fix the bug and commit the fix in one or more separate commits.

$ git commit -m "Fixed severe production problem"
[hotfix-1.2.1 abbe5d6] Fixed severe production problem
5 files changed, 32 insertions(+), 17 deletions(-)

Finishing a hotfix branch
When finished, the bugfix needs to be merged back into master, but also needsto be merged back into develop, in order to safeguard that the bugfix isincluded in the next release as well. This is completely similar to how releasebranches are finished.

First, update master and tag the release.

$ git checkout master
Switched to branch 'master'
$ git merge --no-ff hotfix-1.2.1
Merge made by recursive.
(Summary of changes)
$ git tag -a 1.2.1

Edit: You might as well want to use the -s or -u flags to signyour tag cryptographically.
Next, include the bugfix in develop, too:

$ git checkout develop
Switched to branch 'develop'
$ git merge --no-ff hotfix-1.2.1
Merge made by recursive.
(Summary of changes)

The one exception to the rule here is that, when a release branch currentlyexists, the hotfix changes need to be merged into that release branch, insteadof develop. Back-merging the bugfix into the release branch willeventually result in the bugfix being merged into develop too, when therelease branch is finished. (If work in develop immediately requires thisbugfix and cannot wait for the release branch to be finished, you may safelymerge the bugfix into develop now already as well.)
Finally, remove the temporary branch:

$ git branch -d hotfix-1.2.1
Deleted branch hotfix-1.2.1 (was abbe5d6).

Summary

While there is nothing really shocking new to this branching model, the “bigpicture” figure that this post began with has turned out to be tremendouslyuseful in our projects. It forms an elegant mental model that is easy tocomprehend and allows team members to develop a shared understanding of thebranching and releasing processes.
A high-quality PDF version of the figure is provided here. Go ahead and hang iton the wall for quick reference at any time.

How to delete a remote GIT branch

2011-11-10T09:27:00.001-03:00

From Chapter 3 of Pro Git by Scott Chacon:

Deleting Remote Branches
Suppose you’re done with a remote branch — say, you and your collaborators are finished with a feature and have merged it into your remote’s master branch (or whatever branch your stable codeline is in). You can delete a remote branch using the rather obtuse syntax git push [remotename] :[branch]. If you want to delete your serverfix branch from the server, you run the following:
$ git push origin :serverfix
To git@github.com:schacon/simplegit.git
 - [deleted]         serverfix
Boom. No more branch on your server. You may want to dog-ear this page, because you’ll need that command, and you’ll likely forget the syntax. A way to remember this command is by recalling the git push [remotename] [localbranch]:[remotebranch] syntax that we went over a bit earlier. If you leave off the [localbranch] portion, then you’re basically saying, “Take nothing on my side and make it be [remotebranch].”

Causas zombie

2011-10-31T10:23:00.004-03:00

A lo largo de los internets he visto guías, libros, infografías y textos sobre todo lo que debe saberse para sobrevivir a un apocalipsis zombie. MAL, muy mal. La cultura del desastre es importante, pero la cultura de la prevención lo es aún más. La mejor forma de combatir a un zombie es evitar que aparezca. Es por eso que he creado esta entrada:

Fuente: http://www.cinismoilustrado.com/2011/10/causas-zombie.html

Add forwards search to bash command history

2011-10-25T14:17:00.001-03:00

While using the bash console, ctrl+r command comes extremely handy to search backwards through the command history. But while searching backwards, we may want to be able to navigate both ways. This is not activated by default.

How to activate it? Just run this command:

$ stty -ixon -ixoff

Tadaa! And now you can do ctrl+r and ctrl+s to navigate backwards and forwards.

Update locate database for Mac Os X

2011-09-29T13:11:00.001-03:00

Simple command:

$ sudo /usr/libexec/locate.updatedb

How to install GTK and PyGTK in Mac OS X Lion

2011-09-27T09:05:00.001-03:00

I run into some problems trying to install GTK and PyGTK, but I found a workaround, so here's the trick:

You'll need to have brew installed in your system. If you don't have brew installed, you can installed just by running this command:

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.github.com/gist/323731)"

Now you are ready to go!

Install GTK: just run this command:

$ brew install gtk

Install PyGTK:

Download this: link.
It is a Mac installer package. Install it.

That's it!

You can test your installation from a Python console this way:

$ python
>>> import pygtk

How to change blogger's default language?

2011-09-26T23:42:00.001-03:00

Weird hidden option, you can set Blogger's / Blogspot's default language from this link:

http://www.blogger.com/language.g

Short post :)

Salud!

Delete all "Thumbs.db" files

2011-09-26T23:36:00.001-03:00

I haven't used windows for about 5 years now. Lucky me! I now see the world with better eyes and my hair health has certainly improved jeje.

Anyway, some trash always remains and have to be taken care of. Like the hideous "Thumbs.db" files that windows creates everywhere.

How to get rid of them?

First, find out how many of them you have, by running this command:

find . -iname "Thumbs.db"

And just run the following command in the base folder from where to erase them:

find . -iname "Thumbs.db" -delete

You can do just the same for the "desktop.ini" files.

Saludos!

Procrastinando una atrocidad, inspirado por @ralsina :P

2011-09-24T16:02:00.000-03:00

Acá en PyConAr Junín 2011, inspirado por unos comentarios que hizo @ralsina en una charla, surgiéronme estas atrocidades, que tenía que compartir:

[matias@MacBookPro]:~$ python
Python 2.7.1 (r271:86832, Jun 16 2011, 16:59:05)
[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.15.00)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> def f():
... print 'f()'
...
>>> def g():
... print 'g()'
...
>>> def h():
... print 'h()'
...
>>> a = 0
>>> b = 1
>>> c = 2
>>> (f, g, h)[a or b or c]()
g()
>>> (f, g, h)[a and b or c]()
h()
>>> (f, g, h)[a and (b or c)]()
f()
>>> (f, g, h)[(a and b) or c]()
h()

Smells like teen spirit, de Nirvana, versión acústica

2011-09-17T16:27:00.002-03:00

Tremenda versión acústica de este temazo de Nirvana:

Aprendiendo de los errores: secuencia de videos.

2011-09-16T14:24:00.000-03:00

Vi estos 4 videítos geniales y ¡no podía no compartirlos!

Recomiendo mirarlos en orden.

Salud!

The Evolution of 'Star Trek' (Infographic)

2011-09-16T12:53:00.000-03:00

Source: SPACE.com: All about our solar system, outer space and exploration

Después de haber laburado más de 10 horas hoy....

2011-09-15T00:39:00.001-03:00

.... llegar al final del día logrando esto, es.... en un modo muy particular, maravilloso! jeje

Acá la cosa en cuestión que me hizo feliz ver:

----------------------------------------------------------------------
Ran 414 tests in 232.764s

OK
Destroying test database for alias 'default' ('test_cpi_mrp3')...

Sí señor! Sí señor! Ahora sí puedo hacer un push a origin e irme a dormir :)

How to install meld in Mac OS X Lion

2011-09-13T17:30:00.000-03:00

Missing the nice and sweet meld program for your SVN or GIT diffs in Lion?

Try this:

Get and install pygtk:

http://downloads.sourceforge.net/project/zero-install/PyGTK/2.24.0/PyGTK.pkg

Get meld

http://ftp.gnome.org/pub/gnome/sources/meld/1.5/meld-1.5.2.tar.bz2

Extract the tar.bz2, go to the extracted directory and then run:

Note: This assumes you have brew installed. If not, see here.

$ brew install intltool
$ brew install gettext

$ export PATH=/usr/local/Cellar/gettext/0.18.1.1/bin/:$PATH
$ make prefix=/usr/local/ install

Now you should now have the 'meld' command available.

Some useful links I went through to figure the above mentioned steps:

http://meld.sourceforge.net/
http://meld.sourceforge.net/install.html
http://www.mail-archive.com/pygtk@daa.com.au/msg20559.html

Piloteando un día complicado, en el día del programador

2011-09-13T15:57:00.001-03:00

Bueno, no todos los días son lindos, simpáticos, brillantes y afortunados. Hasta hay veces en que escribo en mi blog en castellano y sólo porque sí, y no para acordarme y compartir algún tip técnico.

Por ejemplo, hoy empecé mi día pornográficamente temprano, con todos los tests y mi instancia local(sí, soy programador, hoy es el día del programador, y nótese no puse eso entre mis desgracias del día jeje), se me rompió el cosito que hace que salga el agua del inodoro, me golpeé la rodilla con una silla y me cayó perfume en un ojo.

Pero podría ser peor. Por ejemplo, me podría haber caído perfume en el otro ojo también. O en vez de la rodilla me podría haber golpeado la ingle.

Pero toda esta racionalización en la vastísima mayoría de los casos no sirve de nada: uno simplemente se pega unas encabronadas tremendas. El punto de este post es, por si acaso les sirviera, compartirles algo que de vez en cuando me mejora un poquito el humor en estos días parcialmente nublados.

¿Qué hago para desencabronarme un poquito en días como hoy?

Bueno, suelo tomarme un té de boldo y leer el Desiderata. ¿Qué es el té de boldo? Bueno, eso no es tan importante. Tomen la infusión que prefieran, estimo que va a funcionar de cualquier modo.
¿Qué es el Desiderata? Les transcribo un poquito de Wikipedia, para poner contexto a la cuestión:

Desiderata (del latín desiderata "cosas deseadas", plural de desideratum) es un poema muy conocido sobre la búsqueda de la felicidad en la vida. Sus derechos de autor son del año 1927 y pertenecen a Max Ehrmann. Desiderata fue publicado en 1948 (después de la muerte de su autor) en una colección de poemas titulada Desiderata of Happiness, recopilados por la esposa de Ehrmann.
En la década del 60 circuló sin la atribución a Ehrmann, a veces con la afirmación de que había sido encontrado en la iglesia St. Paul de Baltimore, en Maryland, Estados Unidos. También se decía que había sido escrito en 1692 (año de la fundación de la iglesia). Sin embargo, esta poesía ha mantenido el sello de Ehrmann en algunas de sus ediciones.

Fuente: http://es.wikipedia.org/wiki/Desiderata

Bueno, ya que estamos en esto, el Desiderata en sí, es este:

“Camina plácidamente entre el ruido y las prisas,

y recuerda que la paz puede encontrarse en el silencio.

Mantén buenas relaciones con todos en tanto te sea posible, pero sin transigir.

Di tu verdad tranquila y claramente;

Y escucha a los demás,

incluso al torpe y al ignorante.

Ellos también tienen su historia.

Evita las personas ruidosas y agresivas,

pues son vejaciones para el espíritu.

Si te comparas con los demás,

puedes volverte vanidoso y amargado

porque siempre habrá personas más grandes o más pequeñas que tú.

Disfruta de tus logros, así como de tus planes.

Interésate en tu propia carrera,

por muy humilde que sea;

es un verdadero tesoro en las cambiantes visicitudes del tiempo.

Sé cauto en tus negocios,

porque el mundo está lleno de engaños.

Pero no por esto te ciegues a la virtud que puedas encontrar;

mucha gente lucha por altos ideales

y en todas partes la vida está llena de heroísmo.

Sé tu mismo.

Especialmente no finjas afectos.

Tampoco seas cínico respecto al amor,

porque frente a toda aridez y desencanto,

el amor es tan perenne como la hierba.

Acepta con cariño el consejo de los años,

renunciando con elegancia a las cosas de juventud.

Nutre la fuerza de tu espíritu para que te proteja en la inesperada desgracia,

pero no te angusties con fantasías.

Muchos temores nacen de la fatiga y la soledad.

Más allá de una sana disciplina,

sé amable contigo mismo.

Eres una criatura del universo,

al igual que los árboles y las estrellas;

tienes derecho a estar aquí.

Y, te resulte o no evidente,

sin duda el universo se desenvuelve como debe.

Por lo tanto, mantente en paz con Dios,

de cualquier modo que Le concibas,

y cualesquiera sean tus trabajos y aspiraciones,

mantente en paz con tu alma

en la ruidosa confusión de la vida.

Aún con todas sus farsas, cargas y sueños rotos,

éste sigue siendo un hermoso mundo.

Ten cuidado y esfuérzate en ser feliz”.

How to fix Brew Update Error ( mxcl / homebrew, Mac OS X Lion)

2011-09-13T15:43:00.003-03:00

Did you, like myself, get something like this while running a brew update?

[matias@MacBookPro]:~ $ sudo brew update
Password:
remote: Counting objects: 588, done.
remote: Compressing objects: 100% (253/253), done.
remote: Total 455 (delta 348), reused 298 (delta 193)
Receiving objects: 100% (455/455), 52.32 KiB, done.
Resolving deltas: 100% (348/348), completed with 124 local objects.
From http://github.com/mxcl/homebrew
* branch            master     -> FETCH_HEAD
error: The following untracked working tree files would be overwritten by merge:
        .gitignore
        Library/Aliases/0mq
        Library/Aliases/4store
(.... lots of lines ....)
        Library/Formula/android-sdk.rb
        Library/Formula/angband.rb
        Library/Formula/ansifilter.rb
        Library/Formula/antiword.rb
        Library/Formula/antlr.rb
        Library/Formula
Aborting
Error: Failed while executing git pull origin master

The fix is easy. Luckily. Goes like this:

$ sudo chown -R `whoami` /usr/local
$ cd /usr/local
$ git reset --hard origin/master
$ cd

Now you can try again:

[matias@MacBookPro]:local (git: master ?) $ brew update
From http://github.com/mxcl/homebrew
3dc7fe2..09ebe32 master -> origin/master
Updated Homebrew from 3dc7fe29 to 09ebe32c.
==> New formulae
aespipe fuse4x fuse4x-kext ntfs-3g parmetis s3fs scotch sshfs
==> Removed formulae
unix2dos
==> Updated formulae
(.... lots of stuff here ....)

Cómo Instalar NINJA IDE en Mac OS X Lion

2011-09-09T13:25:00.001-03:00

Hace poquito actualicé mi compu a Lion y reinstalé NINJA. Con Diego Sarmentero hicimos luego una mini-sprint para dejar NINJA andando aceitadamente y bien nativo en Mac.

Acá les dejo las instrucciones para instalar NINJA desde el repositorio en desarrollo:

Instalar XCode desde el App Store:

http://itunes.apple.com/us/app/xcode/id448457090?mt=12

Instalar HomeBrew:

https://github.com/mxcl/homebrew/wiki/Installation

Instalar Qt y PyQt:

$ brew install qt
$ brew install pyqt
Agregar esta línea en el archivo ~/.profile:

export PYTHONPATH=/usr/local/lib/python:$PYTHONPATH

Hacer un checkout del repositorio de NINJA:

Hace falta tener instalado Mercurial para hacer el clone del repositorio. Si no lo tenés instalado, lo podés instalar así:

sudo easy_install mercurial

$ cd ~
$ mkdir NINJA_IDE
$ cd NINJA_IDE
$ git clone https://github.com/ninja-ide/ninja-ide.git ninja-ide
$ cd ninja-ide

Ejecutar NINJA:

Vamos a la carpeta del checkout:

$ cd ~/NINJA_IDE/ninja-ide/
$ python ninja-ide.py

Y ahora, a disfrutar de NINJA-IDE!

Disable autocorrection in Mac OS X Lion

2011-09-09T13:10:00.001-03:00

I found that Mac OS X Lion came by default with an autocorrection functionality. This can be useful... or a big annoyance!

For instance, it annoyed me when I typed "TRAC" and replaced it with "trace" in one of my daily SCRUM meetings.

Then, how to disable it?

Go to System Preferences -> Language and Text -> Text tab, and disable the check:

Done!

Mac OS X Lion, Python, Django and how I'm happier now with my computer

2011-09-07T10:14:00.000-03:00

I recently upgraded my MacBook Pro from Snow Leopard to Lion.

The idea of the upgrade unsettled me quite a bit since I use my computer to work and having it off due to OS or setup issues was not an option. Basically I was worried about having problems to install Python packages(I work mostly as a Django/Python developer, and I use a bunch of stuff from PyPi and quite a few Django pluggables) and I've already had some nasty problems installing, for instance, the MySQL connector in the past in Snow Leopard.

After some hesitation, I finally got myself to the task of upgrading.

After I upgraded, I did all the setup of the Python stuff: all the virtualenvs, Python/Django packages, the requirements for NINJA-IDE, everything WORKED PERFECT. I did not have a single issue. Nor even a single one. I'm happy this of not having to write a long, strange and tricky post saying something like "yes, it is a huge pain in the... patience", because it is just not. Everything work perfect.

I believe that the root cause of the difference relies in Mac OS Lion to came bundled with 64-bit versions of Python pre-installed:

It has, pre-installed:

32-bit Python 2.5
64-bit Python 2.6 (I use this one for work)
64-bit Python 2.7 (I use this for NINJA-IDE, both for running it and to develop the code I write for it)

That's good new that Apple got its OS with more Python magic :)

Tip of the day: how to add a Firefox Persona to favorites?

2011-09-07T10:01:00.002-03:00

I didn't find how to do that rightaway, I had to do a little googling.

Here's how if you find yourself wondering around the same question:

- go to getpersonas.com
- create an account(if you don't already have one)
- login
- then, on the details page for any persona, in the top-right, just above the image will be a button that says "Add to favorites" (if you are signed in).
- If you have the "Personas addon" installed, you'll be able to see the Personas you add to favorites listed, which is usefull if you, for instance, reinstall Firefox and want to keep its appearance the same:

Installing cairo and pycairo in Mac OS X with python 2.6

2011-08-09T14:22:00.000-03:00

Mac OS X includes an old version of Cairo(usually 1.8.6) which is too old for new software to link against. For the installation of py2cairo to succeed, we need 1.8.10.

Let's check which version we have:

$ pkg-config --atleast-version=1.8.10 cairo
$ echo $?
1

That means there's no a version 1.8.10 or above of the 'cairo' lib.

Let's install it using Brew:

$ brew install cairo

Let's now check again:

$ pkg-config --atleast-version=1.8.10 cairo
$ echo $?
1

No luck again! Why? We need to tell the system where the recently installed version of cairo lives:

$ export PKG_CONFIG_PATH=

Note: In my case, the path is: /usr/local/Cellar/cairo/1.10.2/lib/pkgconfig/

Let's check again:

$ pkg-config --atleast-version=1.8.10 cairo
$ echo $?
0

Awesome!

Let's now install py2cairo, the Python binding for cairo:

1. Download this.
2. Uncompress, go inside the directory.
3. Run the following command, expecting an output like the depicted below:

$ ./waf configure
./set_options
./init
./configure
Checking for program gcc or cc           : /usr/bin/gcc
Checking for program cpp                 : /usr/bin/cpp
Checking for program ar                  : /usr/bin/ar
Checking for program ranlib              : /usr/bin/ranlib
Checking for gcc                         : ok
Checking for program python              : /Users/matias/Dev/CPI/Env/bin/python
Checking for Python version >= 2.6.0     : ok 2.6.1
Checking for library python2.6           : yes
Checking for program python2.6-config    : /usr/local/bin/python2.6-config
Checking for header Python.h             : yes
Checking for cairo >= 1.8.10             : yes
'configure' finished successfully (0.416s)
./shutdown

4. Now build:

$ ./waf build

5. Install:

$ ./waf install

6. Update your PYTHONPATH(you may want to add this line at the bottom of your ~/.profile):

export PYTHONPATH=/usr/local/lib/python2.6/site-packages/:$PYTHONPATH

7. Check everything worked:

$ python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import cairo
>>> cairo.version
'1.8.10'

Happiness!

FYI: The output of the configure, build and install commands in my case was the following(I include it for reference, in case it might be of any help):

(Env)matias@[13:51:34]:pycairo-1.8.10 $ ./waf configure ./set_options
./init
./configure
Checking for program gcc or cc           : /usr/bin/gcc
Checking for program cpp                 : /usr/bin/cpp
Checking for program ar                  : /usr/bin/ar
Checking for program ranlib              : /usr/bin/ranlib
Checking for gcc                         : ok
Checking for program python              : /Users/matias/Dev/CPI/Env/bin/python
Checking for Python version >= 2.6.0     : ok 2.6.1
Checking for library python2.6           : yes
Checking for program python2.6-config    : /usr/local/bin/python2.6-config
Checking for header Python.h             : yes
Checking for cairo >= 1.8.10             : yes
'configure' finished successfully (0.416s)
./shutdown
(Env)matias@[13:52:07]:pycairo-1.8.10 $ ./waf build
./set_options
./init
Waf: Entering directory `/Users/matias/Dev/CPI/Stuff/pycairo-build'
./build
src/build
[1/9] cc: src/cairomodule.c -> ../pycairo-build/default/src/cairomodule_2.o
[2/9] cc: src/context.c -> ../pycairo-build/default/src/context_2.o
[3/9] cc: src/font.c -> ../pycairo-build/default/src/font_2.o
[4/9] cc: src/path.c -> ../pycairo-build/default/src/path_2.o
[5/9] cc: src/pattern.c -> ../pycairo-build/default/src/pattern_2.o
[6/9] cc: src/matrix.c -> ../pycairo-build/default/src/matrix_2.o
[7/9] cc: src/surface.c -> ../pycairo-build/default/src/surface_2.o
[8/9] copy: pycairo.pc.in -> ../pycairo-build/default/pycairo.pc
In file included from /usr/X11/include/X11/Xlib.h:64,
                 from /usr/local/Cellar/cairo/1.10.2/include/cairo/cairo-xlib.h:44,
                 from ../pycairo-1.8.10/src/surface.c:1360:
/usr/X11/include/X11/Xosdefs.h:145:1: warning: "_DARWIN_C_SOURCE" redefined
In file included from /System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/Python.h:8,
                 from ../pycairo-1.8.10/src/surface.c:32:
/System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/pyconfig.h:1075:1: warning: this is the location of the previous definition
[9/9] cc_link: ../pycairo-build/default/src/cairomodule_2.o ../pycairo-build/default/src/context_2.o ../pycairo-build/default/src/font_2.o ../pycairo-build/default/src/path_2.o ../pycairo-build/default/src/pattern_2.o ../pycairo-build/default/src/matrix_2.o ../pycairo-build/default/src/surface_2.o -> ../pycairo-build/default/src/_cairo.so
Waf: Leaving directory `/Users/matias/Dev/CPI/Stuff/pycairo-build'
'build' finished successfully (0.764s)
./shutdown
(Env)matias@[14:05:51]:pycairo-1.8.10 $ ./waf install
./set_options
./init
Waf: Entering directory `/Users/matias/Dev/CPI/Stuff/pycairo-build'
./build
src/build
* installing src/pycairo.h as /usr/local/include/pycairo/pycairo.h
* installing /Users/matias/Dev/CPI/Stuff/pycairo-build/default/src/_cairo.so as /usr/local/lib/python2.6/site-packages/cairo/_cairo.so
* installing /Users/matias/Dev/CPI/Stuff/pycairo-build/default/pycairo.pc as /usr/local/lib/pkgconfig/pycairo.pc
Waf: Leaving directory `/Users/matias/Dev/CPI/Stuff/pycairo-build'
* installing src/__init__.py as /usr/local/lib/python2.6/site-packages/cairo/__init__.py
* byte compiling '/usr/local/lib/python2.6/site-packages/cairo/__init__.py'
'install' finished successfully (0.832s)
./shutdown

Más inventos!

2011-08-09T08:45:00.000-03:00

Fuente: http://www.educar.org/inventos/lineadeltiempo/default.asp

Ordenamos en este sitio cronológicamente los descubrimientos e invenciones que ha realizado el hombre desde los principios de la humanidad.

Los sucedidos en los milenios anteriores a la era cristiana son cálculos aproximados. Asimismo en muchos de los inventos hay variaciones en las fechas de su aparición en los diversos documentos consultados, por lo que pueden resultar ser aproximadas.

Desde el 20.000 a. de C. al 1 d. de C.
Fechas	Inventos y datos relacionados	Eventos
20.000 aC 18.000 aC 18.000 aC	Agujas de hueso Pinceles Cabañas de hueso de mamut	Se realizan las primeras herramientas de piedra
13.000 aC 12.000 aC 10.500 aC	Arpones Cestería en mimbre Vasijas de arcilla	Se comienzan a domesticar perros (11.000)
10.000 aC 8.000 aC 7.500 aC 6.500 aC 6.000 aC 5.500 aC 5.000 aC	Redes de pesca Peine Canoas Fundición de cobre Ladrillo Rueda Balanza	Extinción de mamuts de pelo(10.000) Primeras cosechas en Medio Oriente (8.000)
3.500 a 4.000 aC 3.500 aC 3.300 aC 3.000 aC 1.747 aC 1.500 aC 600 aC Siglo III aC 150 aC	Embarcaciones de vela Arado Escritura Cuneiforme Ábaco Calendario Fundición del Hierro Monedas La palanca El tornillo sin fin El tornillo elevador de agua La rueda dentada La balanza hidrostática Los espejos ustorios Sismoscopio	Alrededor del 3.500 comienza la Edad de Bronce. Arquímedes (287-212 a.C.), notable matemático e inventor griego, nacido en Siracusa, Sicilia, y educado en Alejandría, Egipto, se anticipó a su época con investigaciones e inventos.
Año 1 al 1499 d. de C.
Fechas	Inventos	Eventos
50 105 124 200 a 300 350 400 a 500	Herradura Papel Cúpula Carro con ruedas Estribos Astrolabio	0-33 Vida y Pasión de Jesucristo. 300 - El Cristianismo se ha difundido en el Imperio Romano Fines del Siglo V: Caída del Imperio Romano de Occidente (476). Comienzo de la Edad Media.
650 800 a 900 800 a 900 868 950 999 800 a 1.100	Molino de Viento Papel Moneda Pólvora Impresión de libros Arado de ruedas Cristales coloreados en ventanas de Inglaterra Partituras	Pleno desarrollo precolombino de las civilizaciones aborígenes americanas, especialmente Mayas, Aztecas, Chibchas e Incas. En el S. X aparece la herradura para caballos y un arnés
1.000 1.000 1.100 1.105 1.118 1.121 1.200 1.232 1.257 1.268 1.272 1.280 1.298 1.400 1.420 1.450 Siglo XV	Lentes Cámara oscura Brújula magnética Primer molino de viento en Francia Cañón (Usado por los moros) Clavecín Timón de popa Globos de aire caliente (China) Espejos cóncavos Anteojos Máquina de bobinas de seda en Bolonia Reloj mecánico Rueda de hilar Pinturas al óleo Velocípedo Imprenta de tipos móviles Laúd	Hacia 1140- "Mio Cid" - Dos juglares de Medinacelli componen el primer texto en lengua romance castellano. 1271. Parte de Venecia Marco Polo rumbo a China. En el S. XIV se perfecciona la fabricación del vidrio y se inventa el telar a pedal. 1492 - Descubrimiento de América.
Año 1500 a 1699
Fechas	Inventos	Eventos
1.500 1.500	Reloj (1.500) Puntilla (1.500)	1522 - Sebastián Elcano completa el viaje alrededor del mundo. 1530- Comienza el comercio de esclavos
1.565 1.581 1.569 1.589 1.589 1.590 1.593	Lápiz Péndulo Mapa en proyección Telar Inodoro Microscopio compuesto Termómetro de agua	1589: Sir John Harrington (GB) inventa el inodoro con depósito, pero pasó mucho tiempo antes de imponerse, y se siguieron usando bacines y retretes con agujeros hacia pozo o foso.
1.609 1.620 1.620 1.640 1.642	Telescopio refractor Diligencia Submarino Bayoneta Calculadora de Pascal	1605 / 1615: Cervantes publica "El Ingenioso Hidalgo Don Quijote de La Mancha" 1620: Arriba el "Maryflower" a América del Norte.
1.657 1.665 1.668 1.672 1.687	Reloj de péndulo Microscopio mejorado Telescopio reflector Bomba neumática Higrómetro	Halley descubre el cometa denominado con su nombre (1682)
Año 1700 a 1899
Fechas	Inventos	Eventos
1.709 1.710 1.712 1.714 1.731 1.733 1.740 1.740 1.742 1.745	Piano Termómetro de alcohol Máquina de vapor Newcomen Termómetro de mercurio Octante Lanzadera automática Estufa Franklin Imprenta en colores Escala centígrada Condensador eléctrico	Fundación en 1.724, de la Academia de Ciencias de Rusia
1.752 1.757 1.761 1.763 1.769 1.776 1.782 1.783 1.784 1.785 1.790 1.795 1.796 1.796	Pararrayos Sextante Cronómetro Reflectores Parabólicos Automóvil de vapor Volante Máquina de vapor Watt Globo de aire caliente Lámpara de aceite, con mecha hueca Electróforo Hélice Sistema métrico Vacuna Litografías	1.789: Revolución Francesa Termina la Edad Moderna y comienza la Edad Contemporánea.
1.800 1.801 1.801 1.801 1.802 1.803 1.805 1.816 1.821 1.827 1.830 1.831 1.834 1.837 1.837 1.838 1.839 1.840 1.840 1.842 1.846 1.846 1.846 1.848	Martillo Pilón Pila eléctrica Electróforo Endiómetro Locomotora de Vapor Acumulador eléctrico Telar Jacquard Lámpara de seguridad para mineros Termoelectricidad Fósforos Cortadora de césped Dínamo eléctrica Cosechadora Telégrafo eléctrico Alfabeto Morse Estereoscopio Bicicleta Estampilla de Correos Buques con casco de hierro Reloj eléctrico Anestésicos Saxofón Prensa rotativa Cerradura de seguridad	Napoleón es derrotado en Waterloo (1.815)
1.851 1.860 1.860 1.870 1.876 1.876 1.877 1.877 1.880 1.884 1.885 1.885 1.888 1.889 1.890 1.890 1.894 1.894 1.897 1.897 1.899	Cámara de placas Linóleo Esquiladora Máquina de escribir Teléfono Frigorífico Fonógrafo Motor de cuatro tiempos Bombita eléctrica Generador de turbina de vapor Automóvil Bicicleta de pedales Gramófono Ascensor eléctrico Rayos X El tubo de Crookes Radio Primer periscopio Motor Diesel Motor eléctrico compacto	El motor de cuatro tiempos inventado por Otto (Al. 1877) permitió la invención del automóvil Luis Pasteur, en 1881 comenzó sus experimentos contra la rabia.
Año 1900 a la actualidad
Fechas	Inventos	Eventos
1.900 1.900 1.901 1.902 1.903 1.903 1.903 1.903 1.903 1.906 1.907	El dirigible rígido Zeppelin Tractor Mecano Frenos de disco Cuchilla de seguridad Máquina de hacer botellas Electrocardiograma Cinturón de Seguridad Osito de peluche Lámpara Termoiónica Lavarropas	En 1901, Marconi emite un mensaje de radio a través del Océano Atlántico. Se abre el Canal de Panamá en 1904
1.910 1.911 1.913 1.913 1.913 1.914 1.914 1.916	Se funda la Sociedad de Inventores Argentinos. Modelo nuclear del átomo Acero inoxidable Cadena de montaje Heladera Eléctrica Cremallera Semáforos luminosos Limpiaparabrisas	Comienza la Primera Guerra Mundial (1.914). Albert Einstein desarrolla y enuncia su teoría de la Relatividad (1.915).
1.920 1.921 1.922 1.925 1.926 1.927 1.927 1.928 1.929	Secador de Pelo Autopistas Se funda el Círculo Argentino de Inventores. Contador Geiger Televisor Tostadora Caucho sintético Antibióticos Ciclotrón	Se engrandece la figura del Mahatma Gandhi, en su posición contra el gobierno británico en la India.
1.930 1.931 1.932 1.933 1.933 1.934 1.935 1.938 1.938 1.938	Motor a Reacción Microscopio Electrónico Guitarra Eléctrica Grabaciones Estéreo Polietileno Nylon Radar Café Instantáneo Fotocopiadora Bolígrafo	1936: Guerra Civil Española 1939: Comienza la Segunda Guerra Mundial
1.941 1.942 1.942 1.943 1.946 1.946 1.946 1.947 1.948 1.949	Aerosoles Reactor Nuclear Equipo de Inmersión Turbina de reacción para aviones Horno de Microondas Calculadora electrónica Computadora Transistor Long Play - Disco de Larga Duración Neumáticos Radiales	La Bomba atómica destruye Hiroshima y Nagashaki, Japón, en 1.945
1.950 1.954 1.954 1.955 1.956 1.956 1.957 1.958 1.959 1.959	Tarjeta de Crédito Central Nuclear Radio a transistores Plancha de vapor Velcro Video Cámara Satélite Espacial Aerodeslizador Chip de Silicio Lycra	Mediante arduas investigaciones, se descubre la estructura del ADN (1.953). Realizan el ascenso al Everest, en 1.953, Hillary y Tenzing
1.960 1.962 1.962 1.963 1.964 1.969	Teflón Robot Industrial Satélite de Comunicaciones Video Casettera Procesador de Textos Avión Jumbo	El hombre posa su pie en la luna. En 1.969 los astronautas estadounidenses llegan a la Luna.
1.971 1.972 1.972 1.973 1.974 1.978 1.979 1.979	Reloj Digital Escáners Rayos X Video juegos domésticos Protocolo de Internet (IP) y Protocolo de Control de Transmisión (TCP) Códigos de Barras Computadora Personal Walkman Catalizadores para automotores	Nace el primer bebe de probeta, en 1978.
1.980 1.981 1.981 1.982 1.982 1.982	Cubo de Rubik Transbordador Espacial Papeles autoadhesivos Tarjeta inteligente Corazón Artificial Discos Compactos	Explosión del reactor nuclear de Chernobyl en 1986. Cae el Muro de Berlín en 1989
1.990 1.990 1.990 1.990 1.991 1.993 1.994 1.995 1.999 2.000	Realidad Virtual Fusión Nuclear Identificador de voz Se funda la Asociación Argentina de Inventores y la Escuela Argentina de Inventores. Videófono Se realiza en Buenos Aires el Primer Congreso Iberoamericano de Inventores Se celebra en Argentina el 50° Aniversario de la invención del bolígrafo. El Correo Argentino emite estampillas conmemorativas, en honor de Biro, y otros inventores argentinos destacados: Pescara, Cristiani y Finochietto. Internet: se populariza el uso de redes con protocolos TCP/IP Se crea en Argentina la Fundación Biro, en el centenario del nacimiento de Ladislao José Biro. Se organiza en Buenos Aires el Simposio Internacional de Inventores (WIPO-IFIA Symposium), por primera vez en el hemisferio Sur	Invasión a Kuwuait por parte de Irak en 1990. Se agilizan las comunicaciones instantáneas y se afianza el concepto de globalización

Algunos inventos argentinos

2011-08-09T08:42:00.001-03:00

Buscando algunos inventos por año en que se inventaron, dí con este sitio, que me resultó más que interesante. Siguiendo mi recorrido por el sitio, encontré una sección dedicada a recopilar algunos de los inventos que se hicieron en Argentina y/o por argentinos/as.

Acá van algunos:


Fecha	Inventor	Invento
1810	Miguel Colombise	Nuevo control de navegación para aeróstatos.
1813	Andrés Tejeda	Máquina hiladora.
1813	Fray Luis Beltrán	Herramientas metalúrgicas, arneses y batanes para el Ejército de los Andes.
1876	Elías O´Donell	Nuevo tipo de aeróstato.
1891	Juan Vucetich	Sistema Dactiloscópico para la identificación de las personas.
1914	Luis Agote	Instrumentos para la transfusión sanguínea. Realiza por primera vez en el mundo una transfusión con sangre almacenada.
1916	Raúl Pateras de Pescara	Primer helicóptero eficaz en la historia de la aviación.
1917	Quirino Cristiani	Tecnología para realizar dibujos animados. Filma el primer largometraje de dibujos animados.
1925	Vicente Almandos Almonacid	Sistema de navegación nocturno de aviones y guías para bombarderos.
1928	Ángel Di Césare y Alejandro Castelvi	Colectivo
1929	Francisco Avolio	Amortiguador hidroneumático
1930	Enrique Finochietto	Instrumental quirúrgico, por ejemplo el separador intercostal a cremallera
1953	José Fandi	Secador de pisos de una sola pieza, instrumento doméstico
1968	Jorge Weber	Tapa de rosca degollable
1970	Eduardo Taurozzi	Motor pendular de combustión interna
1970	Juan Bertagni	Plano sonoro
1979	Francisco De Pedro	Soporte fijo para marcapasos
1983	Mario Dávila	Semáforo para ciegos
1989	Carlos Arcusín	Jeringa autodescartable. Capuchón de seguridad para agujas hipodérmicas
1994	Claudio Blotta	Camilla automática para emergencias

Fuente: http://www.educar.org/inventos/inventosargentinos.asp

Rename a GIT branch

2011-07-19T08:47:00.000-03:00

One of the(bunch of) features of GIT that make it a delight to use while developing is the branching capabilities.

Using a good branching model even facilitates the collaboration when working with a team and helps going towards better results.

But, well, let's get to the point: sometimes it happens that you create a branch and later on you realize that the name you gave to it was not the best. Nevermind: you can painlessly rename it this way:

git branch -m old_branch_name new_branch_name

Yes! GIT rules! :)

The best of Red Hot Chili Peppers playlist

2011-07-14T15:04:00.000-03:00

How to amend a commit message in GIT

2011-07-07T13:06:00.000-03:00

If the commit you want to fix isn’t the most recent one:

git rebase --interactive $parent_of_flawed_commit
If you want to fix several flawed commits, pass the parent of the oldest one of them.
An editor will come up, with a list of all commits since the one you gave.
1. Change pick to reword (or on old versions of Git, to edit) in front of any commits you want to fix.
2. Once you save, git will replay the listed commits.
Git will drop back you into your editor for every commit you said you want to reword, and into the shell for every commit you wanted to edit. If you’re in the shell:
1. Change the commit in any way you like.
2. git commit --amend
3. git rebase --continue

Most of this sequence will be explained to you by the output of the various commands as you go. It’s very easy, you don’t need to memorise it – just remember that git rebase --interactive lets you correct commits no matter how long ago they were.

Source: link.

UPDATE:

Another way to go:

git commit --amend

Used to amend the tip of the current branch. Prepare the tree object you would want to replace the latest commit as usual (this includes the usual -i/-o and explicit paths), and the commit log editor is seeded with the commit message from the tip of the current branch. The commit you create replaces the current tip -- if it was a merge, it will have the parents of the current tip as parents -- so the current top commit is discarded.
It is a rough equivalent for:
$ git reset --soft HEAD^
$ ... do something else to come up with the right tree ...
$ git commit -c ORIG_HEAD
but can be used to amend a merge commit.

Source: link.

How to install MySQL Server and Python connector in Mac OS X Snow Leopard

2011-07-05T17:58:00.000-03:00

================================================================
-> MySQL Server and Python connector(Mac OS X Snow Leopard):
================================================================

Here goes some tricky stuff. You may want to consider getting yourself a cup of
linden infusion :-P

--> If you have a previous MySQL version:

If you have a previous MySQL version, perhaps a 32 bit one, you may encounter several
problems to perform the upgrade to a newer, 64-bit version. But don't worry, the
following steps should get you going in no time.

Hands on!
To uninstall the previous version, do this *in order*:

- First you need to go to: /Library/Receipts and look for a file named
'InstallHistory.plist' (It's just a regular property list)
- Open it and look for the entries regarding MySQL, and delete them.

MacBookPro:~ matias$ cd /Library/Receipts/
MacBookPro:Receipts matias$ sudo nano InstallHistory.plist
ctrl+shift+w, look for the entries regarding MySQL and delete them.
ctrl+o (save) ctrl+x (exit)

- As the installer receipts are actually located in a different place on Snow Leopard:

MacBookPro:Receipts matias$ cd /private/var/db/receipts/
MacBookPro:receipts matias$ ls *mysql*
com.mysql.mysql.bom com.mysql.mysqlstartup.bom
com.mysql.mysql.plist com.mysql.mysqlstartup.plist
MacBookPro:receipts matias$ sudo rm *mysql*

- Now we are ready to do the uninstall work per se, by doing these *in order*:

* Use mysqldump or MySQL Admin to backup your databases to text files!
* Stop the database server
* sudo rm /usr/local/mysql
* sudo rm -rf /usr/local/mysql*
* sudo rm -rf /Library/StartupItems/MySQLCOM
* sudo rm -rf /Library/PreferencePanes/My*
* edit /etc/hostconfig and remove the line MYSQLCOM=-YES-
* rm -rf ~/Library/PreferencePanes/My*
* sudo rm -rf /Library/Receipts/mysql*
* sudo rm -rf /Library/Receipts/MySQL*
* sudo rm /etc/my.cnf

--> Install MySQL (server, startup item, pref pane):

- Install mysql's x86_64 version from the .dmg file. Download the .dmg from
here: http://dev.mysql.com/downloads/mysql/5.1.html#downloads
(I also put the installers under '3rdparty/MacOSX_Installers' folder).

--> Install MySQLdb in the virtualenv

- Turn the virtualenv on. This command does the trick:

MacBookPro:~ matias$ laexpo_start
(Env)MacBookPro:~ matias$

- Fetch MySQL-python-1.2.3 from here: http://sourceforge.net/projects/mysql-python/.
I'll assume you downloaded the .tar.gz file to the Desktop.

- Unpack the tarball, enter the folder:

(Env)MacBookPro:~ matias$ tar xzf MySQL-python-1.2.3.tar.gz
(Env)MacBookPro:~ matias$ cd MySQL-python-1.2.3

- Open the 'site.cfg' file and edit the 'mysql_config' to poin to the path where
you mysql_config resides. For me it is '/usr/local/mysql-5.1.50-osx10.6-x86_64/bin/mysql_config'

- Open the 'setup_posix.py' file and set the 'mysql_config.path' to the same path
you did in the previous step(line 26). Should end up looking like this:

mysql_config.path = "/usr/local/mysql-5.1.50-osx10.6-x86_64/bin/mysql_config"

- Compile the thing:

(Env)MacBookPro:~ matias$ cd ~/Desktop/MySQL-python-1.2.3
(Env)MacBookPro:MySQL-python-1.2.3 matias$ python setup.py clean
(Env)MacBookPro:~ matias$ ARCHFLAGS='-arch x86_64' /usr/bin/python setup.py build
(Env)MacBookPro:~ matias$ ARCHFLAGS='-arch x86_64' python setup.py install

* NOTE 1: It is critical to have the virtualenv activated before running the above
listed command. If it is not, the installation of MySQLdb will be done in
the system and no in the virtualenv and therefore MySQLdb will not be
available when you turn the virtualenv on.

* NOTE 2: It is also critical to set the compilation flags correctly. If not set
correctly, the compilation will default to 32-bit architecture and will
not work afterwards with MySQL.

* NOTE 3: DON'T USE 'sudo' FOR THE COMPILLATION/INSTALL COMMANDS. If you do so, you'll
be installing MySQLdb to the system and not to the virtualenv.

- Confirm the process worked ok:

(Env)MacBookPro:MySQL-python-1.2.3 matias$ python
Python 2.6.1 (r261:67515, Dec 17 2009, 00:59:15)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
>>> MySQLdb.version_info
(1, 2, 3, 'final', 0)

How to share files with VirtualBox between Mac and Windows

2011-06-29T14:50:00.000-03:00

Today I needed to setup a windows xp(!!!)!/(&)(&/%/&!·$/&!$////!!!!!) virtual machine with Virtual Box at work. Doing that, I happened to need files from mi computer to be accessible from the virtual machine with windows xp.

How did I get that done? Well, I used the guide of this excellent post(which I borrow here :P ): link.

Here it goes:

I recently felt the need of changing my VMWare Fusion 2.0 Beta, because it kept on locking my Mac. I found VirtualBox, which is recently acquired by Sun, offered for free and has a recent release 1.6. I read some nice reviews, and although it lacks some features, looks like it’s quite fast and reliable (will review it when I get to use it more).

First thing I needed to do with VirtualBox, after setting up a Windows was to share files between my Mac (Leopard) and Windows (XP). VirtualBox does not offer drag and drop for now, but hopefully will do soon. To share files between 2 computers:

1. Install Guest Additions

Go to “Devices->Install Guest Additions”. After selecting this, open “My Computer”, and you will see there is Guest Additions installer mounted. Just double click and install. After installing, do not forget to reboot (that’s important).

2. Create a shared folder

Go to “Devices->Shared Folders”. Press “Add” (+ sign on right side). Browse for your shared folder on your mac. Pick up a good name and note it down (we will use the name later on). I suppose you selected a folder to share and named it “shared”.

3. Create a batch file

On Windows XP, shared folders are browsable. Easiest way to mount shared folders is to create a batch file, instead of writing a command each time you login. To do that, right click on Desktop, select “New->Text file”. Rename your text file to “Mount.bat” (or something else you wish). After renaming, right click on it and select “Edit” and paste the code below (with necessary modification, depending on your shared folder name. I assume it’s “shared” in our case)

net use x: \\vboxsvr\shared

Beware of the space in between “x:” and “\\” otherwise you will get;

System error 67 has occured

Which in my opinion a common mistake. Save the file and you are done. Just double click on “Mount.bat” on your desktop and you will see X: drive will appear with your shared folder on My Computer.

Enjoy :)

Muy buena película de Woody Allen: "Si la Cosa Funciona"(Whatever works) (2009)

2011-06-27T16:26:00.002-03:00

Ayer vi esta película, como despedida de domingo, antes de irme a dormir.

"Whatever works", dirigida y escrita por Woody Allen. Me gustó mucho, así que la recomiendo vía blog post :)

Cuevana | Si la Cosa Funciona (2009)

Para arrancar la semana con un poco de Bécquer

2011-06-27T09:48:00.000-03:00

Yo sueño que estoy aquídestas prisiones cargado, y soñé que en otro estado más lisonjero me vi. ¿Qué es la vida? Un frenesí. ¿Qué es la vida? Una ilusión, una sombra, una ficción, y el mayor bien es pequeño; que toda la vida es sueño, y los sueños, sueños son.

Installing psycopg2 inside a virtualenv in Mac OS X

2011-06-14T12:09:00.001-03:00

If you tried to install psycopg2 inside a virtualenv in Mac OS X and got something like this:

(Env)MacBookPro:proj matias$ ARCHFLAGS="-arch i386 -arch x86_64" pip install --upgrade psycopg2
Downloading/unpacking psycopg2
Downloading psycopg2-2.4.2.tar.gz (666Kb): 666Kb downloaded
Running setup.py egg_info for package psycopg2
Error: pg_config executable not found.

Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:

python setup.py build_ext --pg-config /path/to/pg_config build ...

or with the pg_config option in 'setup.cfg'.
Complete output from command python setup.py egg_info:
running egg_info
creating pip-egg-info/psycopg2.egg-info
writing pip-egg-info/psycopg2.egg-info/PKG-INFO
writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
warning: manifest_maker: standard file '-c' not found
Error: pg_config executable not found.

Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:

python setup.py build_ext --pg-config /path/to/pg_config build ...

or with the pg_config option in 'setup.cfg'.
----------------------------------------
Command python setup.py egg_info failed with error code 1
Storing complete log in /Users/matias/.pip/pip.log

The issue is that psycopg depends on pg_config command, and if you don't have it, you can't install psycopg.

That got it fixed for me:

export PATH=/Library/PostgreSQL/8.4/bin/:"$PATH"

Now, let's go again:

(Env)MacBookPro:proj matias$ ARCHFLAGS="-arch i386 -arch x86_64" pip install psycopg2
Downloading/unpacking psycopg2
Running setup.py egg_info for package psycopg2
no previously-included directories found matching 'doc/src/_build'
Installing collected packages: psycopg2
(....lot's of lines of output here....)
Successfully installed psycopg2
Cleaning up...

Done!

KASHMIR chords, with Jimmy Page, Jack White, & The Edge

2011-06-10T17:30:00.001-03:00

Un-freaking-believable!

Estreno version mobile de mi blog!

2011-06-08T11:28:00.000-03:00

Desde ahora, mi blog tiene activada la opción y los templates para poder ser visualizado en dispositivos móviles. Cuando me olvide de algún comando o algún truquito acerca del cual hice un post, voy a poder buscarlo desde el iPod :)

Buen miércoles, gente!

How to determine if you are running a 32 or 64 bit version of Python?

2011-06-08T11:25:00.000-03:00

Just run the this in a Python shell:

import ctypes
print ctypes.sizeof(ctypes.c_voidp)*8

In my case, it goes this way:

MacBookPro:~ matias$ python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> print ctypes.sizeof(ctypes.c_voidp)*8
64
>>>

Super geek TCP/IP jokes

2011-06-07T08:06:00.000-03:00

Overheard at the IRC channel, at work:

- A TCP packet walks into a bar and says "bartender, I want a beer!" "You want a beer?" "yes, a beer"
- The good thing with TCP jokes is that the other one always gets them
- The bad thing about UDP jokes is that you can't be sure that the other one got them
- A bunch of TCP packets go into a bar, until it’s overcrowded. The next day, half as many go in.
- The problem with TCP jokes is that people keep retelling them slower until you get them.

What Are Alnico Pickups? Article from Fender® News

2011-05-31T16:18:00.000-03:00

What Are Alnico Pickups?

The same physical properties of alnico found in the child's toy magnet set above also make for great-sounding pickups on the American Deluxe series Stratocaster below.

When guitar shopping at a retail outlet or online, you’re bound to run across mention of alnico pickups. What does that mean? What are alnico pickups and what do they do that non-alnico pickups don’t?

First let’s explain the word itself. Alnico is an acronym comprising the first two letters of three different metallic elements, aluminum, nickel andcobalt.

Second, let’s explain what’s special about alnico. In the early 1930s in Japan, alloys of iron, nickel and aluminum were found to display twice the strength of the best steel magnets of the time. Cobalt was soon found to be a useful addition to the mix, as cobalt alloys are highly corrosion-resistant. Iron alloys that contain alnico display a high resistance to heat and to loss of magnetism, and are hence used to make strong and durable permanent magnets. In fact, before the development of rare earth “super” magnets (i.e., neodymium and samarium-cobalt) in the 1970s and 1980s, alnico magnets were the strongest magnets you could get, capable of producing strength at their poles as high as 3,000 times the strength of the Earth’s magnetic field.

In a nutshell then, alnico alloys make for very strong, long-lasting magnets.

Given their strength and durability, alnico alloys were consequently adopted for widespread consumer applications in which magnets with such properties were especially useful, such as electric motors, sensors, loudspeakers …

And electric guitar pickups. At its simplest, an electric guitar pickup consists of a permanent magnet wrapped in coils of wire, so it stands to reason that high-quality magnets such as those containing alnico would make for high-quality guitar pickups. And that they certainly did—alnico-magnet pickups were found to produce a smooth, warm and highly musical tone.

Sure enough, Fender started making pickups with alnico magnets as early as the late 1940s. Back then, alnico was the high-tech material of the age, and Fender continued to use it through the 1950s and 1960s. Technically more efficient ceramic magnets took over in a wide variety of commercial applications starting in the 1960s, but ceramic-magnet guitar pickups were found to have a generally harsher, more brittle sound with sharper peaks than their alnico predecessors. Many players and hence many manufacturers—Fender included—stuck with the mellower rounded-peak tone of alnico pickups (analogous to “worn shock absorbers” in the words of one pickup expert), and their use continues to this day (more on that presently).

* * * * *

Another element you’ll run into when guitar shopping is that there are different kinds of alnico pickups, usually designated by Roman numerals—i.e., alnico II, alnico III and alnico V (although you do see standard Arabic numerals 2, 3 and 5 just as often, really).

The alnico number is used to differentiate the strength of the magnetic field produced; it designates a sort of “recipe” in which the percentage of the different elements in the alloy varies slightly. While all three are actually pretty close, the type of alnico used, when combined with other elements such as the art of pickup placement, does affects the sound of an electric guitar.

Where it gets a bit strange, however, is that alnico numbers do not increase in order of magnetic strength, as you might at first suppose (i.e., II being the weakest, III in the middle and V the strongest). On the contrary, the order of magnetic strength goes like this: alnico III has the weakest magnetic force; alnico II is in the middle and alnico V is the strongest.

Alnico II is what you find on the earliest Telecaster® guitars of the 1950s. It is especially good for middle-position pickups, and it contributes to a very sweet and musical “vintage-y” sound.

Alnico III is the weakest of the three because it actually contains no cobalt. Since it exhibits the least amount of magnetic pull, it’s the type that impedes free string vibration the least, hence making it a great choice for neck pickups (over which there is usually the greatest amount of string vibration). This is the type used in the first Stratocaster® guitars in the mid-1950s, and use of this particular alnico blend is one of the reasons why their neck pickups sound so amazingly good.

Alnico V is the strongest of the three; more powerful in tone and response. Its greater output makes it a good choice for bridge pickups, over which there is usually a smaller amount of string vibration. Good for an aggressive, punchy sound.

As noted, Fender continues to use alnico pickups in many of its guitars. Good examples include Highway One series guitars, which use alnico III; American Standard and American Special series guitars, which use alnico V; and the American Vintage series ’62 Stratocaster Reissue, which uses three alnico II pickups. And in a nuanced nod to the art and science of pickup construction and placement, current American Deluxe series Stratocaster models have an alnico III neck pickup, and alnico II middle pickup and an alnico V bridge pickup.

Source: http://www.fender.com/news/index.php?display_article=663&EDID=KECT0K4-SQP1-BS9O0-XHUCC-VGOM-v1

Al día de la fecha

2011-05-30T19:54:00.000-03:00

Hoy es para mi un día interesante, intenso lleno de colores, entusiasmos, ansiedades y expectativas.

Y deambulando los vericuetos de mi mente me acordé de un pedacito de la letra de un tema, que me dieron ganas de compartir:

Oh! Inmortal poseidon, el del furioso tridente,
a ti me encomiendo en esta difícil empresa,
propicia que este velero llegue a buen puerto,
permíteme llevar a cabo los designios de Afrodita nacida de las olas,
¡Oh! Calíope, augusta entre las musas,
haz florecer el jardin,
trae la rima.

Salud!

Link a video de Youtube que empiece a reproducir en un instante dado

2011-05-24T17:02:00.002-03:00

Tip interesante:

¿Cómo pasarle un link a alguien de un video de Youtube, pero que cuando lo vea empiece a reproducirse desde cierto minuto y segundo?

Así:

Link base:

http://www.youtube.com/watch?v=-FucbvoFFy0

Momento en que quiero que se empiece a reproducir cuando abra el link:

cero minutos, once segundos

Link con un tiempo en particular para el inicio de reproducción:

http://www.youtube.com/watch?v=-FucbvoFFy0&t=0m11s

Notar el "t=0m11s" al final del link. "t=0m" indica la cantidad de minutos y "11s" los segundos a desplazar, desde el inicio del video, al empezar a reproducir.

Post dedicado al copado de Ale Peralta, que me hizo conocer este truquito.

[Update: ¡Gracias Humitos ( humitos.wordpress.com ) por el comentario! ]

Fix file permissions in Mac OS X

2011-05-23T19:52:00.001-03:00

A few days ago I copied a bunch of files/folders from an external NTFS formatted hard drive to my MacBook. The files where copied ok, but the permissions where messed up.

How did I fix them? With this simple command:

$ chmod -Rv u=rwx,g=rx,o=r username path_to_base_folder

It recursively goes through all files and folders and fix their permissions.

Una araña que se puede comer un pájaro

2011-05-23T15:58:00.000-03:00

Fran Herrero, un amigo de la facu, me pasó esta foto:

¡Sí! ¡es una araña comiéndose un pájaro!

Me puse a buscar un poco. Resulta que se llama "golden orb weaver" ese tipo de arañas. Son enormes y tienen un veneno neurotóxico similar al de las viudas negras(si bien muchísimo menos poderoso).

Muchas imágenes: Link.
Artículo de la Wikipedia, con muchas fotos: Link.

Acordes de Elephant Gun, de Beirut

2011-05-20T20:57:00.001-03:00

Si bien este tema, la banda Beirut lo toca con ukelele, encontré una excelente adaptación para guitarra acá, lugar del cual proviene el resto del contenido de este post.

Update: Para los que, como mi amigo Humitos, quieren ver y escuchar el original, agrego un videíto de Youtube:

Chords

Beirut
Elephant Gun

For ukelele tuned a 1/2 step up (G# C# E# A#)

Am: 2003
D7: 2223
G: 0232
C: 0003
C/B: 0002

To play on guitar, capo VI:

Am(Em): 022003
D7(A7): x02223
G(D): x00232
C(G): 320003
C/B(G/F#): 320002 -or- 2x0003

Intro:

Am D7 G C C/B  x2

Verse:

Am          D7                   G
   If I was young, I'd flee this town

     C      C/B     Am
I'd bury my dreams under - ground
       D7             G             C      C/B
As did I, we drink to die, we drink ton - ight

Am          D7             G
   Far from home, elephant gun
                C    C/B    Am
Let's take them down one by one
             D7                  G                C   C/B
We'll lay it down, it's not been found, it's not ar - ound

Chorus:

Am         D7        G        C     C/B   Am
   Let the seasons begin - it rolls right on
        D7        G              C   C/B  (Am)
Let the seasons begin - take the big king down

Am         D7        G        C     C/B   Am
   Let the seasons begin - it rolls right on
        D7        G              C   C/B  (Am)
Let the seasons begin - take the big king down

Bridge:

Am D7 G C C/B  x4

Am     D7    G
    Oh oh oh oh
   C  C/B (Am)
Oh la la  la   x4

Am D7 G C C/B  x8

Verse:

Am             D7          G          C   C/B     Am
   And it rips through the silence of our camp at night

            D7          G         C  C/B Am
And it rips through the night  oh la la  la

            D7          G              C    C/B Am
And it rips through the silence of our camp at  night
            D7          G                    C       C/B       (Am)
And it rips through the silence, all that is left is all that i hide

Outro:

Am D7 G C C/B to end

Note for Guitarists

The “low” string on a ukulele is higher than the next two subsequent strings. So, while the strings go G C E A, the relative pitches (1 being low, 4 being high) are 3 1 2 4. To replicate the sound, you would have to replace your D string with something much thinner (i.e. whatever you use for your high E) and tune it up an octave.

How to install NINJA-IDE in Mac OS X (Snow Leopard)

2011-05-19T18:17:00.001-03:00

UPDATE: For Mac OS X Lion instructions, see here.

I wrote this for the Wiki of NINJA-IDE project to help people install it after making the port of NINJA to Mac.

How to install in Mac OS X (Snow Leopard)

Introduction

There are many ways to install the requirements for Ninja-IDE to run. Here my
aim will be to write a guide as straightforward as possible to get you runing
Ninja in a glimpse.
Then, I'll give a rough guide for more advanced or curious users than want to
perform their own installation their way(for instance, using a virtualenv).

Details

We'll need to install the following:

Mercurial (to checkout and keep track of Ninja repo in Google Code).
Brew (a.k.a. "HomeBrew", an awesome Mac OS X package installer that resembles apt-get a lot)
Qt
PyQt

Install Mercurial

Go to [http://mercurial.berkwood.com/ http://mercurial.berkwood.com/]
Download and install the latest version of the Mercurial binaries.

Install Brew

* With this command, you get Brew installed to /usr/local.
NOTE: DO NOT RUN THIS COMMAND AS ROOT OR USING SUDO, RUN IT AS A COMMON USER!!

$ ruby -e "$(curl -fsSL https://raw.github.com/gist/323731)"

HomeBrew project site: http://github.com/mxcl/homebrew

Install XCode

You can get the latest version of XCode from Apple [http://developer.apple.com/technologies/xcode.html here]

Install sip, Qt and PyQt

From a console, run the following commands:

$ brew install sip
$ brew install qt
$ brew install pyqt
$ easy_install rope
$ easy_install pygments

Note: Brew downloads the source of the packages and compiles it and as some of the above listed programs are quite big, it is natural for the compilation to take A BUNCH of time.

Check installations:
To check the installation details for the packages you install using brew, run a command like this(in this example, for "pyqt" package):

MacBookPro:Cellar matias$ brew info pyqt
pyqt 4.8.3
http://www.riverbankcomputing.co.uk/software/pyqt
Depends on: sip, qt
/usr/local/Cellar/pyqt/4.7.7 (537 files, 19M)
/usr/local/Cellar/pyqt/4.8 (525 files, 19M)
This formula won't function until you amend your PYTHONPATH like so:
export PYTHONPATH=/usr/local/lib/python:$PYTHONPATH
http://github.com/mxcl/homebrew/commits/master/Library/Formula/pyqt.rb

Clone Ninja-IDE repository:

$ git clone https://github.com/ninja-ide/ninja-ide.git ninja-ide

Run Ninja

$ cd ninja-ide
$ python ninja.py

Note: If you get this error:

MacBookPro:ninja-ide matias$ python ninja.py
Traceback (most recent call last):
File "ninja.py", line 59, in
ninja_ide.setup_and_run() File "/Users/matias/Dev/ninja-ide/ninja_ide/__init__.py", line 40, in setup_and_run from ninja_ide import core, resources File "/Users/matias/Dev/ninja-ide/ninja_ide/core/__init__.py", line 4, in
from ninja_ide.core.core import run_ninja File "/Users/matias/Dev/ninja-ide/ninja_ide/core/core.py", line 6, in
from ninja_ide import gui File "/Users/matias/Dev/ninja-ide/ninja_ide/gui/__init__.py", line 1, in
import qt File "/Users/matias/Dev/ninja-ide/ninja_ide/gui/qt/__init__.py", line 1, in
from ide import IDE File "/Users/matias/Dev/ninja-ide/ninja_ide/gui/qt/ide.py", line 6, in
from PyQt4.QtGui import QMainWindow ImportError: No module named PyQt4.QtGui

add this line to your ~/.profile file to amend your PYTHONPATH:

export PYTHONPATH=/usr/local/lib/python:$PYTHONPATH

Done!

¡Im pre sio nan te! Australia's Got Talent 2011 - Chooka

2011-05-18T13:21:00.001-03:00

Python: Removing duplicates from a list in one line

2011-05-17T16:41:00.000-03:00

Yes, indeed, Python rules:

Let's create a list with duplicated elements:

>>> l = [1,1,1,2,2,1,5,4,3,2,1]

And let's now remove them in just one line:

>>> l2 = list(set(l))

See the result:

>>> l2
[1, 2, 3, 4, 5]

Voilà!

Playing with Python: deciding if two words are anagrams

2011-05-17T16:34:00.000-03:00

Very little script I made that checks if two strings(or words) are anagrams:

def are_anagrams(string1, string2):
string1 = list(string1.lower())
string1.sort()
string2 = list(string2.lower())
string2.sort()
return string1 == string2

If you thought: "Hey, dude, what's an anagram??", take a look here first. Also, this is a very nice online app that finds anagrams for words you provide: http://wordsmith.org/anagram/

¡Nuevo diseño!

2011-05-16T13:41:00.001-03:00

Al fin me decidí y me puse a renovar el diseño de mi blog.

Me gusta cómo quedó :)

Cuento de Joaco

2011-05-16T12:17:00.000-03:00

Mientras Joaco ( http://focojoaco.blogspot.com ), un gran amigo, me daba una mano con un proyecto en Haskell, tuvimos que esperar un ratito que se descargara un archivo. En ese momento, Joaco improvisó un mini cuento.

Les comparto:

cuando la nutria sale de su madriguera, se puede oler el olor a coco rayado de los caramelos m&m que su mama le compraba de pequeña, su mama mandril y su papa oso
listo

Brillante :)

Haskell in TextMate

2011-05-16T12:14:00.000-03:00

How to install the bundle:

mkdir -p /Library/Application\ Support/TextMate/Bundles
cd /Library/Application\ Support/TextMate/Bundles
git clone https://github.com/textmate/haskell.tmbundle

That's it!

Some references here: http://pysvn.tigris.org/project_downloads.html

How to install pysvn inside a virtualenv in Mac OS (Snow Leopard)

2011-05-16T12:11:00.000-03:00

Using the url to the sources is more portable and works in Mac OS X too.
(pip doesn't find it in PyPi), so I set up the pip requirement with the
path to the .tar.gz with the source:

$ http://pysvn.barrys-emacs.org/source_kits/pysvn-1.7.5.tar.gz

If you are using a virtualenv, you'll need to create a symlink. Something like this:

$ ln -s /Library/Python/2.6/site-packages/pysvn/ /lib/python2.6/site-packages/pysvn

Check it worked:

(Env)MacBookPro:viaadmin matias$ python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysvn
>>> pysvn.version
(1, 7, 5, 1360)

How to install pycripto in Mac OS X Snow Leopard

2011-05-09T14:32:00.000-03:00

The command:

$ pip install pycrypto

throws this error:

(....lots of lines....)
error: command 'gcc-4.2' failed with exit status 1

try this(it worked perfect for me):

$ ARCHFLAGS="-arch i386 -arch x86_64" pip install pycrypto

ipdb sometimes goes crazy too

2011-05-09T11:19:00.000-03:00

Debugging a post request from a Django dev server with ipdb, I got that:

ipdb> print request.FILES.get('data_dict.pickle')
None
ipdb> request.python(3743,0x1019c1000) malloc: *** error for object 0x101cf5950: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug

Just wanted to share that :)

Django mode for TextMate

2011-05-06T13:49:00.000-03:00

Developing with Django using TextMate?

Take a look at this!

http://code.djangoproject.com/wiki/TextMate

Installation:

mkdir -p /Library/Application\ Support/TextMate/Bundles
cd /Library/Application\ Support/TextMate/Bundles
svn co http://svn.textmate.org/trunk/Bundles/Python%20Django.tmbundle/
git clone https://github.com/textmate/python-django-templates.tmbundle.git

Usage:

Just set the language of your files to "Python Django" and that's it!

PEP8 check in TextMate

2011-05-06T13:44:00.000-03:00

I think any serious programmer that codes with Python should try to get his/her code as close as possible to PEP8.

Many IDEs have their own way to perform static PEP8 code checks. If you use TextMate, here is a way to go:

https://github.com/astrofrog/python-pep8-tmbundle

Installation:

cd ~/Library/Application\ Support/TextMate/Bundles/
git clone git://github.com/astrofrog/python-pep8-tmbundle.git "Python PEP8.tmbundle"
cd Python\ PEP8.tmbundle/
git submodule init
git submodule update
osascript -e 'tell app "TextMate" to reload bundles'

Usage:

shift + crtl + command + v

And that's it!

Más sobre Papúa Nueva Guinea

2011-05-05T15:39:00.000-03:00

Estuve mirando un poquito en la Wikipedia el artículo de tal país(acá).

Resulta que la capital se llama Port Moresby y es un país megadiverso.

Acá va una foto del puerto de la capital:

¡Bonito lugar! :)

Objetivo para este año: quiero tener una visita en mi blog de alguien de Papua y Nueva Guinea

2011-05-05T15:11:00.000-03:00

Bueno, eso, antes que termine el año quiero tener una visita en mi blog de alguien de Papua y Nueva Guinea.

Porque, después de todo, ¿Quién dijo que todos los objetivos de uno tienen que ser cosas elegantes y suntuosas como "implementar un algoritmo de ordenación de O(1)", "plantar 12 mil árboles", "escribir un libro" o así?

Make svn ignore some files

2011-05-05T15:02:00.000-03:00

Here goes another post for something I forget all the time how to do: telling svn to ignore some files:

$ svn propedit svn:ignore .

This will open a text editor. Write the filenames, extensions, whatsoever you want svn to ignore(like "*.pyc", "*.db", etc), save the file and commit.

That's it!

De cero a Django en 30 minutos: videos de la charla

2011-05-01T02:53:00.000-03:00

PyDay Córdoba - Mi charla sobre Django

2011-05-01T01:14:00.000-03:00

Después de la choripaneada, el ping pong con la gente de PyAr, los comentarios super apasionados respecto de las bases de datos no relacionales de Emiliano Marcozzi y las infaltables y fabulantásticas charlas geek, termina el PyDay Córdoba 2011.

Estuvo muy bueno, la verdad. Excelente la organización de Juan BC.

De paso, aprovecho este post y dejo el material de mi charla sobre Django:

https://github.com/matiasherranz/scoobygalletas/tree/master/PyDay_Cba2011

Están las filminas(pasadas a PDF) y el código completo del ejemplo que mostré. Cualquier cosa, ya saben, me tiran un mail a scoobygalletas@gmail.com.

Saludos!

John Mayer - Heart of Life (Acoustic)

2011-04-27T12:39:00.000-03:00

How to install PIL on Snow Leopard

2011-04-27T11:06:00.000-03:00

For all the unfortunate like me that came across the pain it involves to correctly install PIL to use Django ImageFields in Mac (Snow Leopard) here goes what worked for me:

MacBookPro:~ matias$ sudo -s
bash-3.2# ARCHFLAGS="-arch i386 -arch x86_64" pip install PIL

"sudo -s" is needed because ARCHFLAGS doesn't seem to get passed into sudo.

Running a mail server with Python(for development)

2011-04-21T16:07:00.000-03:00

This post aims mostly to stop forgetting this super useful command:

sudo python -m smtpd -n -c DebuggingServer localhost:25

If it may comes handy to someone else too, greater news then :-)

Arnet Vs. freenode.net: the banned IP case

2011-03-21T11:38:00.000-03:00

First thing in the morning, I get up, make some coffee, connect to work's IRC. But today that didn't work as usual, the IP the ISP assigned me was on a black list:

NOTICE * *** Looking up your hostname...
NOTICE * *** Checking Ident
NOTICE * *** Found your hostname
NOTICE * *** No Ident response
465: You are banned from this server- You have a host listed in the DroneBL. For more information, visit dronebl.org/lookup_branded.do?ip=190.230.24.15 Please contact proxyscan@freenode.net with questions.
ERROR Closing Link: host15.190-230-24.telecom.net.ar (*** Banned )

Renewing the IP got the trick done.

Bug vs Feature

2011-02-21T09:26:00.001-03:00

Un parrafito de Montaigne

2011-02-17T21:07:00.000-03:00

"Yo soy de la partida. Aquellos que siguen el camino opuesto, el de complacerse en ellos mismos, el de estimar lo que tienen por encima del resto y no reconocer ninguna forma más hermosa que la que tienen ante sus ojos, si no son más avisados que nosotros, con seguridad son más felices. No envidio en absoluto su sabiduría, pero sí su buena suerte."

- Montaigne

Dale Carnegie quotes

2011-02-15T14:41:00.000-03:00

I read some books written by Dale Carnegie and found lots of interesting stuff on them, so, here goes my post dedicated to him, including a link to a page of some of his quotes.

Quotes here: http://bit.ly/Dale_Carnegie

Backup/Restore a MySQL dump from the console

2011-02-03T09:30:00.000-03:00

Given that tools like MySQL Administrator or MySQL Query Browser most usually won't behave very good when it comes to recovering large db backups, moreover if there is UTF-8 stuff in the dump, I decided to go for the mysql shell, which does much better.

Here some useful commands to have handy:

Dump ALL MySQL Databases

mysqldump --user=XXXXXXXX --password=XXXXXXX -A > PATH_TO_SQL_DUMP_FILE.SQL

Dump Individual or Multiple MySQL Databases

mysqldump --user=XXXXXXXX --password=XXXXXXX --databases DB_NAME1 DB_NAME2 DB_NAME3 > PATH_TO_SQL_DUMP_FILE.SQL

Dump some particular tables from a MySQL Database

mysqldump --user=XXXXXXXX --password=XXXXXXXX --databases DB_NAME --tables TABLE_NAME > PATH_TO_SQL_DUMP_FILE.SQL

If you want to make sure of not having backwards compatibility issues from the MySQL Server versions between your development and production environments, you may want to add this to the commands:

--compatible=mysql323

Reloading the full contents of a database:

Unzip the backup file you wish to use.
Open it up and pull out only the information that you will need.
Save this text file.
Use the following command to feed back in the contents of a text file:

mysql --verbose --user=XXXXXXXX --password=XXXXXXXX DB_NAME < PATH_TO_SQL_DUMP_FILE.SQL

Django: Dump your database contents to(SQL data) into an xml file

2011-02-03T09:21:00.000-03:00

To dump all the data in your Django project's db into a nice xml fixture, just run the following command:

python manage.py dumpdata --format=xml APP_NAME > SOME_FIXTURES_FOLDER/APP_NAME/initial_data.xml

Update:

As Fabi[1] correctly (and violently jeje :-P) pointed out, json is much cooler:

python manage.py dumpdata --indent=4 data.json

[1] @caffeineGalli at Twitter and his site: http://from-the-cloud.com/

Upgrading Django 0.96 to 1.2.4: tuning up model fields

2011-02-01T12:23:00.000-03:00

Continuing with the last post, here goes a script I made to upgrade the fields of the models.

The script is here. The upgrade reference is here: "Porting your apps from Django 0.96 to 1.0".

Add CSRF token to all your Django templates in a glimpse.

2011-02-01T12:07:00.000-03:00

Recently, in my work(at Machinalis: www.machinalis.com) I had the tough experience of having to upgrade a Django app built with Django 0.96 to Django 1.2.4.

I had to deal with things like oldforms, newforms, ObjectPaginator, changing 'maxlength' to 'max_length' in models fieleds and a long list of etc's.

But it came the time for me to deal with integrating csrf to all the giant bunch of forms there around... And that's not meant to be done by a human being :-P

So, I created a Python script for that. You can get it from my GiHub here.

Appart from that, you'll need to add this 'django.middleware.csrf.CsrfViewMiddleware' to MIDDLEWARE_CLASSES in settings.py and, depending on the nature of your project, making several changes more. I'd suggest taking a look(as I did) at the Django Project Reference on CSRF here.

More scripts I made to help upgrading Django 0.96 to 1.2.4 coming soon!

Instalar Geany en Mac OS X 10.5.8

2009-12-09T16:00:00.004-03:00

Ayer estrené proyecto en el trabajo: desarrollar una aplicación para iPhone.

Como no podría ser de otro modo, para desarrollar una app para estos adorables telefonillos, tengo que usar Mac OS. Así que me puse a buscar la forma de instalar Geany, una de mis IDEs favoritas, en Mac.

Lo encaré usando Darwin Ports. Vamos con el paso a paso:

1. (si no lo tenés instalado de antes) Instalar Darwin Ports. Descargar el .dmg de acá http://darwinports.com/download/ La instalación es muy sencilla (tan sólo doble click en el dmg una vez que se haya descargado y seguir los pasos que indique).

2. En una consola, ejecutar estos comandos:

$ sudo port -d selfupdate
$ sudo port install geany

¡Y listo! Pueden pegar una mirada al sitio del proyecto Geany acá: http://www.geany.org/

[UPDATE]

También se puede instalar usando brew, un excelente manejador de paquetes para Mac:

no soy un gran fan de macports o fink, a decir verdad, pero brew me gusta mucho.

Para instalar homebrew: https://github.com/mxcl/homebrew

Una vez instalado:

Actualizamos la información de los paquetes(brew les llama "formulas"):

matias@[08:59:36]:~ $ brew update

Pedimos información sobre el paquete/formula de Geany:

matias@[08:53:52]:~ $ brew info geany
geany 0.20
http://geany.org/
Depends on: pkg-config, gettext, intltool, gtk+
Not installed
http://github.com/mxcl/homebrew/commits/master/Library/Formula/geany.rb

Lo instalamos:

matias@[09:02:16]:~ $ brew install geany

Listo!

Iterating over a dictionary in Django templates

2009-09-24T12:29:00.000-03:00

Just a quick one: To iterate over a list you do something along the lines of:

{% for item in list%}{{ item }}{% endfor %}

But this fails (silently, of course) for dictionaries and the magic you are looking for is to call .items on the dictionary then iterate key,value across that:

{% for key,value in dictionary.items %}{{ value }}{% endfor %}

Edit: This is now covered in the django documentation itself.

Artículo original: acá.

on the fly PEP8 compliance check for Emacs

2009-09-19T15:12:00.000-03:00

Hola!

Hace unos días estuve buscando algún plugin para Geany que hiciera chequeo de PEP8 compliance. No encontré :-P

¡Pero! Sí encontré cómo hacerlo con el majestuoso Emacs (gracias a Gustavo por la ayuda!):

¿Cómo?
Nota: Asumo Ubuntu 9.04 y Emacs.

A por ello:
Primero: instalar pychecker y flymake

matias@terpsicores:~$ sudo apt-get install pychecker
matias@terpsicores:~$ sudo easy_install flymake

Descargar flymake.el y pep8.py.

Más acerca de PEP8 acá.

Copiar flymake.el dentro de ~/emacs.d/

matias@terpsicores:~$ cp flymake.el ~/emacs.d/

Copiar pep8.py en /usr/bin/ y darle los permisos adecuados:

matias@terpsicores:~$ sudo cp pep8.py /usr/bin/
matias@terpsicores:~$ sudo chmod 755 /usr/bin/pep8.py

Copiar esto dentro de ~/.emacs

(when (load "flymake" t)
(defun flymake-pylint-init ()
   (let* ((temp-file (flymake-init-create-temp-buffer-copy
                      'flymake-create-temp-inplace))
          (local-file (file-relative-name
                       temp-file
                       (file-name-directory buffer-file-name))))
         (list "pep8.py" (list "--repeat" local-file))))

(add-to-list 'flymake-allowed-file-name-masks
              '("\\.py\\'" flymake-pylint-init)))

Acá dejo una copia de mi .emacs, por si acaso.

Por último, teniendo abierto algún archivo .py, en Emacs:

x
flymake-mode

Y listo!

Todo lo que siempre quiso saber ....

2009-09-18T23:54:00.001-03:00

.... y nunca se animó a preguntar a su Project Manager acerca de Mercurial, en una sola imagen.

matias@terpsicores:~$ python -c "print 'Hello, world'"

2009-09-18T22:57:00.000-03:00

Como es debido, tenía que hacerme mi blog.

Hace rato que venía postergando la tarea de armar un espacio en el que ir poniendo los know how de las cosas a las que les voy encontrando la vuelta (por ejemplo, si alguien intentó instalar Mercurial en Mac OS X con la versión de Python -2.5- que viene preinstalada, me va a entender inmediatamente).

Bueno, basta de cháchara, al fin me hice el blog.

Salud!

Matías [scoobygalletas].-