Marcelo Fernández: Fedora Day Buenos Aires 2014

La comunidad Fedora Argentina se complace en anunciar el evento más importante de Fedora en el país hasta el momento:

¡El Sábado 13 de Diciembre los esperamos en la UTN de Medrano 951, CABA, para celebrar el Fedora Day!

Será un día con charlas de varios ponentes de Argentina y Latinoamérica, donde se hablará del futuro de la distribución y de varias tecnologías como Ovirt, Docker, Openshift, etc. También estaremos celebrando el Release Party de la nueva versión de Fedora, Fedora 21, ¡con la posibilidad de instalarlo en sus computadoras o en un pendrive para llevarlo!

Si desean participar en el evento no duden en registrarse de forma gratuita en el siguiente link [1].

También iremos actualizando la información del Fedora Day en la página oficial [2] y en la wiki de Fedora [3].

Si estás interesado en dar una charla sobre “inserte tema aquí” relacionado con Fedora no dudes en registrarte en nuestra lista de correos [4] y enviarnos tu propuesta.

En Fedora es muy importante para nosotros la comunidad y es por eso que estamos buscando nuevos colaboradores. Si estás interesado, no te pierdas nuestras charlas al respecto o acercate a cualquier colaborador el día del evento.

Ante cualquier duda o consulta por favor contactate con Matías <delete@fedoraproject.org> o con Rino <villadalmine@fedoraproject.org>

¡¡¡Los esperamos!!!

Saludos,
Fedora Argentina

1. http://goo.gl/zYsClS
2. http://fedoraday.com
3. https://fedoraproject.org/wiki/Fedora_Day_Buenos_Aires_2014
4. https://lists.fedoraproject.org/mailman/listinfo/argentina

Martín Gaitán: Las cosas chiquitas que cambian el mundo

Nota

Tengo dos weblogs. Este es en el que escribo artículos técnicos o que tienen que ver de alguna manera con mi profesión. Textos y pretextos es igual de personal, pero me sale —me sale cada vez menos, tristemente— de otras tripas, quizás para otro público.

Sin embargo, quiero hacer una excepción con este post, porque probablemente tenga más alcance aquí y es algo que me atraviesa todas las facetas: las ganas de hacer de este que pisamos, un mejor mundo.

Desde el 2005, a las poquitas semanas de haberme venido a vivir a Córdoba, hasta no sé que día del 2012, cada sábado de todas las semanas del año, me tomé dos bondis (o uno, cuando me iba a pata hasta el centro), para llegar a Campo de La Ribera. Mazamorra, la agrupación, fue mi espacio de militancia, mi usina de amistad, mi cobijo del dar y recibir. Sobre todo del recibir.

Nota

El dominio está caído, pero refloté un backup de la web acá

Enseñé a multiplicar, salté la soga, hice barriletes, leí cuentos, metí goles con pelotas improvisadas, los relaté, discutí mucho, reí mucho más, escuché, aprendí. Recibí el pan, el mate y el abrazo de muchas familias, en sus ranchos sin lujos, rebalzados de ganas de devolver amor con más amor. Fui payaso, serigrafista y amigo. Conocí niños que hoy, adultos, van a ser papás. Todavía nos vemos, conversamos, algunos vienen a mi casa de vez en cuando, a veces voy yo.

Muchos de esos compañeros y compañeras y, sobre todo, los vecinos y vecinas de Campo de la Ribera, siguen metiéndole el tiempo, el ingenio y el amor perseverante a esas cosas chiquitas, que son las que cambian el mundo.

Son cosas chiquitas. No acaban con la pobreza no nos sacan del subdesarrollo, no socializan los medios de producción y de cambio, no expropian las cuevas de Alí Babá. Pero quizá desencadenen la alegría de hacer, y la traduzcan en actos. Y al fin y al cabo, actuar sobre la realidad y cambiarla aunque sea un poquito, es la única manera de probar que la realidad es transformable.

—Eduardo Galeano

Durante muchos años, el anhelo de la organización fue tener un espacio físico, un lugar de encuentro en el barrio que permita no sólo mejorar las condiciones para realizar actividades (como el apoyo escolar o la copa de leche), sino profundizar la relación con los vecinos y su participación, que es, claro está, el objetivo primordial.

Por diversas razones organizativas o rispideces con los poderes fácticos del barrio (punteros/narcos), ese objetivo se fue postergando año tras año.

Pero ahora existe, es un sueño redondo y grande, que ya casi despierta: el Domo de Campo de la Ribera.

Hacen falta $15.000 (quince mil pesos) para terminar de techarlo y ponerlo en condiciones, para que en el 2015 se siga transformando, mejorando con fuerza, desde ese barrio de Córdoba, este mundo que pisamos.

Podés donar con tarjeta de crédito u otros medios de pagos desde esta página.

¡Lo que puedas será bienvenido!

Mariano Guerra: Overtone, clojure, jackd, alsa in ubuntu 14.10

ok, this is a small dump of what I did, I'm surely missing some stuff and surely it won't work as is for you, but maybe it does and you are as happy as I'm right now generating noise (not as happy as anyone close to me at this moment).

all the things I think I installed:

sudo apt install alsa-tools alsaplayer-jack alsa-utils pulseaudio-module-jack supercollider jack-tools fftw3 qjackctl openjdk-8-jdk

yes, you can see the desperation there with some stuff that may not make sense, but at least it works..

you need to install leiningen, it's really easy and it has good instructions on the site so I won't go into details, just follow the instructions here: http://leiningen.org/

then I follow the instructions from overtone's wiki here:

https://github.com/overtone/overtone/wiki/Installing-overtone

before starting our repl and rocking like a hurricane we need to kill pulseaudio and start jack, it sounds easier than it is because pulseaudio just won't stay dead :(

the way I found to make it work was to edit pulseadio client.conf:

sudo vim /etc/pulse/client.conf

uncomment the line (remove the semicolon):

; autospawn = yes

and leaving it like this:

autospawn = no

I added myself to the audio group, not sure if it's required but just in case:

sudo adduser $USER audio

for this to take effect you need to logout and login again, to make sure you have the group, open a terminal and run:

groups

you should see audio between some other groups, if you can't see it try rebooting or replacing $USER with your actual username in the adduser command.

now stop pulseaudio:

pulseaudio --kill

then start jackd, I tried all the combinations I could find on the internet without success, this is the one that worked for me:

jackd -R -d alsa -d hw:1

if that doesn't work try:

jackd -R -d alsa

or try the versions that are recommended on the overtone wiki:

jackd -r -d alsa -r 44100

or:

jackd -r -d alsa -r 44100 -P

you can also try running qjackctl and play with the settings to see if you have luck.

now that we (hopefully) have jackd running, we can start playing with overtone, here is a small dump of a session:

lein new tutorial
cd tutorial

# add [overtone "0.9.1"] to :dependencies
vim project.clj

lein deps
lein repl

# inside the clojure repl
user=> (use 'overtone.live)
user=> (definst foo [] (saw 220))
#<instrument: foo>
user=> (foo)
#<synth-node[loading]: user/foo 35>
user=> (kill 35)

when you are done you can stop jackd from the ui or from the shell however you started it and start again pulseaudio:

pulseaudio --start

some additional note, when I'm using jackd I can't set the volume from the media keys or the sound mixer in the top planel, I run:

alsamixer

press F6, select the output I'm using and change it with the keys (ESC to close).

hope it's useful for someone.

Alberto Paparelli: PyCon-Ar 2014

Paso otra PyCon en Argentina, la sexta. Esta vez fue en Rafaela, Santa Fe.

Llegamos el Jueves a la tarde, por lo que ese día solo participe del sprint de la nueva web de pyar. Hice unos commits, pero no hubo mucho tiempo como para poder aportar mas.

El Viernes y Jueves fueron de charlas. Entre las que más me gustaron estan:

  • Tu propio cliente de Torrent streaming en Python (Por Felipe Lerena y GiLgAmEzH)
  • Django Security quick-wins (Por Andrés Riancho)
  • Prediciendo el mundial con inteligencia artificial (Por Juan Pedro Fisanotti)
  • Trabajando de forma asíncronica en Django/Python (Por Martín Alderete)
Foto grupal PyCon-AR 2014

De las charlas relámpago, me gusto mucho el cuento de Juanjo Conti, que me hizo acordar mucho al estilo de Hernán Casciari.

Con respecto al lugar (Rafaela), es lindo, aunque hay muy poco para hacer y recorrer.

Hernán Grecco: Pint 0.6: faster and with better non-multiplicative units support

I have released version 0.6 of Pint, a Python units library.

Pint is Python package to define, operate and manipulate physical quantities: the product of a numerical value and a unit of measurement. It allows arithmetic operations between them and conversions from and to different units.

It provides a comprehensive and extensive list of physical units, prefixes and constants defined in a standalone text file. The registry can parse prefixed and pluralized forms of units resulting in a much shorter and maintainable unit definition list.

It also provides great NumPy integration without monkey patching or importing a particular module, with implicit unit conversion and an emphasis on correctness.

What's new

The largest change landed in the way Pint handles offset units such as temperatures. It now provides a much better behavior that is both correct and useful. It deals properly with differences of temperatures, providing useful error messages when the requested operation is ambiguous.

There were many bug fixes and other internal changes. Thanks to some optimizations and aggressive caching, Pint continues to get faster in each release. We have also improved the quality of some error messages and parts of the code, and the test coverage is above 90%

There a lot of other improvements, you can look at the full list of changes.

Thanks to the people that contributed bug reports, suggestions and patches since 0.5. In particular to Matthieu Dartiailh, Ryan Kingsbury, Joel Mohler, Virgil Dupras, Jonas Olson, John David Reaver and Peter Grayson. A big thanks should be given to David Linke who did an awesome work with offset units (Please let me know if I am forgetting someone!)

Interested? Install it and give it a try!

Submit your bug reports, comments and suggestions in the Issue Tracker. There are already some ideas for version 0.7. Check them out, comment and add yours.

Read the docs: https://pint.readthedocs.org/
or fork the code: https://github.com/hgrecco/pint

Marcelo Fernández: Pwning hardware

El video dura media hora, pero a mí me gustó muchísimo, aprendí mucho. Mikah Scott es una genia, y se propone investigar cómo customizar el firmware de una lectora/grabadora de CD/DVD/Blu-Ray, para dominarlo por completo, empezando por el microcontrolador ARM que posee. Por ejemplo, moviendo el láser en la posición que uno quiera y dispararlo. Habla un excelente y puntilloso inglés, así que se le entiende palabra por palabra, sugiero que lo vean incluso para practicar su inglés técnico.

Es muy interesante cómo usa Photoshop para visualizar el contenido de un firmware (?!??!?! ¡nunca se me hubiera ocurrido!), y cómo usa IDA (este sí es más lógico) para interpretar el código binario.

Además, usa vusb-analyzer en Ubuntu para visualizar el tráfico USB dumpeado con usbmon o similares, por ejemplo snifeado de una máquina virtual.

Por último, usa iPython para hacer que el ARM y el resto de los chips con los que interactúa (mt1939, dsp) haga lo que uno quiera (todavía está en avance).

Es increíble cómo en el ámbito de seguridad se usa Python (lo confirmé en la Ekoparty en estos días).

Insisto, se aprende muchísimo viendo este tipo de videos: herramientas, técnicas, trucos y fundamentalmente cómo abordar estos desafíos.

Saludos

Hernán Grecco: PyVISA command-line utilities

PyVISA is a Python frontend for the VISA library that enables controlling all kinds of measurement equipment through GPIB, RS232, USB and Ethernet among others interfaces.

If you are following the development of PyVISA you might have seen that we have recently made the visa module executable to provide a few useful utilities. To try this, you need to update to the latest PyVISA:

$ pip install -U https://github.com/hgrecco/pyvisa/zipball/master

First, we now provide a simpler way to get debug information:

$ python -m visa info
Machine Details:
   Platform ID:    Darwin-10.8.0-x86_64-i386-32bit
   Processor:      i386

Python:
   Implementation: CPython
   Executable:     /Users/grecco/envs/lantz/bin/python
   Version:        3.2.3
   Compiler:       GCC 4.2.1 (Apple Inc. build 5666) (dot 3)
   Bits:           32bit
   Build:          Apr 10 2012 11:25:50 (#v3.2.3:3d0686d90f55)
   Unicode:        UCS2

PyVISA Version: 1.6.1

Backends:
   ni:
      Version: 1.6.1 (bundled with PyVISA)
      #1: /Library/Frameworks/visa.framework/visa:
         found by: auto
         bitness: 32
         Vendor: National Instruments
         Impl. Version: 5243392
         Spec. Version: 5243136
   py:
      Version: 0.1.dev0
      ASRL INSTR: Available via PySerial (10.8.0)
      TCPIP INSTR: Available
      USB INSTR: Available via PyUSB (1.0.0rc1). Backend: libusb0


Notice also that more useful information is given, including details about the different backends (in this case ni and py).

Another utility is the VISA shell which was taken from the Lantz project. It provides a way to list, open and query devices. It also allows you to get (and in the near future set) attributes. The shell has in-built help, autocomplete and

$ python -m visa shell
Welcome to the VISA shell. Type help or ? to list commands.

(visa) list
( 0) ASRL2::INSTR
( 1) ASRL1::INSTR
(visa) open ASRL1::INSTR
ASRL1::INSTR has been opened.
You can talk to the device using "write", "read" or "query".
The default end of message is added to each message
(open) attr
+-----------------------------+------------+----------------------------+-------------------------------------+
|          VISA name          |  Constant  |        Python name         |                 val                 |
+-----------------------------+------------+----------------------------+-------------------------------------+
| VI_ATTR_ASRL_ALLOW_TRANSMIT | 1073676734 |       allow_transmit       |                  1                  |
|    VI_ATTR_ASRL_AVAIL_NUM   | 1073676460 |      bytes_in_buffer       |                  0                  |
|      VI_ATTR_ASRL_BAUD      | 1073676321 |         baud_rate          |                 9600                |
|    VI_ATTR_ASRL_BREAK_LEN   | 1073676733 |        break_length        |                 250                 |
|   VI_ATTR_ASRL_BREAK_STATE  | 1073676732 |        break_state         |                  0                  |
|    VI_ATTR_ASRL_CONNECTED   | 1073676731 |                            |          VI_ERROR_NSUP_ATTR         |
|    VI_ATTR_ASRL_CTS_STATE   | 1073676462 |                            |                  0                  |
|    VI_ATTR_ASRL_DATA_BITS   | 1073676322 |         data_bits          |                  8                  |
|    VI_ATTR_ASRL_DCD_STATE   | 1073676463 |                            |                  0                  |
|  VI_ATTR_ASRL_DISCARD_NULL  | 1073676464 |        discard_null        |                  0                  |
|    VI_ATTR_ASRL_DSR_STATE   | 1073676465 |                            |                  0                  |
|    VI_ATTR_ASRL_DTR_STATE   | 1073676466 |                            |                  1                  |
|     VI_ATTR_ASRL_END_IN     | 1073676467 |         end_input          |                  2                  |
|     VI_ATTR_ASRL_END_OUT    | 1073676468 |                            |                  0                  |
|   VI_ATTR_ASRL_FLOW_CNTRL   | 1073676325 |                            |                  0                  |
|     VI_ATTR_ASRL_PARITY     | 1073676323 |           parity           |                  0                  |
|  VI_ATTR_ASRL_REPLACE_CHAR  | 1073676478 |        replace_char        |                  0                  |
|    VI_ATTR_ASRL_RI_STATE    | 1073676479 |                            |                  0                  |
|    VI_ATTR_ASRL_RTS_STATE   | 1073676480 |                            |                  1                  |
|    VI_ATTR_ASRL_STOP_BITS   | 1073676324 |         stop_bits          |                  10                 |
|    VI_ATTR_ASRL_WIRE_MODE   | 1073676735 |                            |                 128                 |
|    VI_ATTR_ASRL_XOFF_CHAR   | 1073676482 |         xoff_char          |                  19                 |
|    VI_ATTR_ASRL_XON_CHAR    | 1073676481 |          xon_char          |                  17                 |
|     VI_ATTR_DMA_ALLOW_EN    | 1073676318 |         allow_dma          |                  0                  |
|    VI_ATTR_FILE_APPEND_EN   | 1073676690 |                            |                  0                  |
|    VI_ATTR_INTF_INST_NAME   | 3221160169 |                            | ASRL1  (/dev/cu.Bluetooth-PDA-Sync) |
|       VI_ATTR_INTF_NUM      | 1073676662 |      interface_number      |                  1                  |
|      VI_ATTR_INTF_TYPE      | 1073676657 |                            |                  4                  |
|       VI_ATTR_IO_PROT       | 1073676316 |        io_protocol         |                  1                  |
|   VI_ATTR_MAX_QUEUE_LENGTH  | 1073676293 |                            |                  50                 |
|   VI_ATTR_RD_BUF_OPER_MODE  | 1073676330 |                            |                  3                  |
|     VI_ATTR_RD_BUF_SIZE     | 1073676331 |                            |                 4096                |
|      VI_ATTR_RM_SESSION     | 1073676484 |                            |               3160976               |
|      VI_ATTR_RSRC_CLASS     | 3221159937 |       resource_class       |                INSTR                |
|  VI_ATTR_RSRC_IMPL_VERSION  | 1073676291 |   implementation_version   |               5243392               |
|   VI_ATTR_RSRC_LOCK_STATE   | 1073676292 |         lock_state         |                  0                  |
|     VI_ATTR_RSRC_MANF_ID    | 1073676661 |                            |                 4086                |
|    VI_ATTR_RSRC_MANF_NAME   | 3221160308 | resource_manufacturer_name |         National Instruments        |
|      VI_ATTR_RSRC_NAME      | 3221159938 |       resource_name        |             ASRL1::INSTR            |
|  VI_ATTR_RSRC_SPEC_VERSION  | 1073676656 |        spec_version        |               5243136               |
|     VI_ATTR_SEND_END_EN     | 1073676310 |          send_end          |                  1                  |
|   VI_ATTR_SUPPRESS_END_EN   | 1073676342 |                            |                  0                  |
|       VI_ATTR_TERMCHAR      | 1073676312 |                            |                  10                 |
|     VI_ATTR_TERMCHAR_EN     | 1073676344 |                            |                  0                  |
|      VI_ATTR_TMO_VALUE      | 1073676314 |                            |                 2000                |
|       VI_ATTR_TRIG_ID       | 1073676663 |                            |                  -1                 |
|   VI_ATTR_WR_BUF_OPER_MODE  | 1073676333 |                            |                  2                  |
|     VI_ATTR_WR_BUF_SIZE     | 1073676334 |                            |                 4096                |
+-----------------------------+------------+----------------------------+-------------------------------------+
(open) close
The resource has been closed.



Again, this release is only possible thanks to the contribution of a lot of people that contributed bug reports, testing and code. Thanks to everybody!

Submit your bug reports, comments and suggestions in the Issue Tracker. We will address them promptly.

Read the development docs: https://pyvisa.readthedocs.org/en/master/
or fork the code: https:/https://github.com/hgrecco/pyvisa/

Gustavo Campanelli: Como recuperé 20 GB de mi disco rígido

Recientemente vi que el juego DC Universe Online se podía jugar gratuitamente, así que decidí darle una oportunidad y bajarlo. Luego de 3 días de descarga (a bajas velocidades mientras jugaba otras cosas, a altas velocidades de noche) lo tuve disponible. Jugué unas 7 horas. y debo decir que me resultaron bastante entretenidas. El comienzo, el escape de la nave de Brainiac, está muy bien diseñado

Marcos Dione: testing-qt4-applicationswith-slots-and-signals

A few days ago someone said something[1] that reminded me about my audio player, which I had abandoned for more than a year already. The reason was mostly that the two Phonon backends, VLC and gstreamer, for some reason or other couldn't play the files I had without any gaps between songs.

To be honest, the first bug end up being me not properly encoding the filenames. If you first URL-encoded the filename and then built a Q/KURL with that, then it's all fine. It took me more than 12 months and a few rereads of the thread to realize it. Fixes apart, it seems that the bug still exists for other instances of gstreamer errors, so we're not out of the woods. In any case, I switched to the VLC backend and it seems that now is able to fire the aboutToFinnish() signal properly, so for the moment I'm using that.

All that is fine, but that's not what I wanted to talk about in this post. Given that this project largely precedes my interest on testing, it has no testing at all. Most of the project is straightforward enough to almost no need any, but there's a critic part that would not suffer at all if it had any, namely the Collections handling, including passing files from one to another and automatically updating new/removed Songs[2].

So after fixing the bug mentioned above I tried to figure out the current state of affaires regarding Collections, and boy, they're in bad shape. The code was locally modified, never commited, deactivating any notifications of filesystem changes (new or removed files), and other code I can't really understand the purpose of.

Because if this last detail is that I decided to start testing three classes: Collection, which handles a set a Songs with a common root directory; CollectionAggregator, which handles a set of collections and should coordinate moving a Song from one Collection to another; and CollectionIndexer, which scans from a Collection's root dir to find Songs.

All went fine while I tested the first class, Collection. There was a tricky part where I had to setup a QApplication in order to make signals work. The problems began when I started testing CollectionIndexer. Tests started blocking endlessly, signals stopped being either emited or firing the connected slots, life was bad.

I tried to search the available documentation and mailing lists for a hint about the problem, but besides a quite complex example that didn't seem to properly converge to anything useful, I was mostly on my own.

This morning I got my eureka moment: I noticed that if I executed each test class by itself, it worked, but both at the same time blocked and never finished. Then I remembered something said in QApplication's documentation:

For any GUI application using Qt, there is precisely one QApplication object, no matter whether the application has 0, 1, 2 or more windows at any given time.

That was it: I was creating the application, first in the setUp() method, then as a class attribute, but I had one test class per class to test, each in its own file. Somehow this last fact lead me to think that somehow they were executed in separate processes, which is not true. Luckily, even with this limitation, there's none on the amount of times you can exec_() and quit() the same instance, so that's what I did: I created only one instance and reused it everywhere. I was already doing that for each test method, but again, somehow having several files mislead me to think they were isolated from each other.

So now all my unit tests work without mysteriously blocking forever. Now I just hope I can keep riding the success wave and bring satyr into good shape. A new release wouldn't hurt.


[1] No matter how much I try, I can't get any vaguer.

[2] Ok, maybe the Player/Playlist combo wouldn't hurt to have UTs either.


satyr pykde python