Planet OCLUG

I have had a real problem with sound on Xubuntu for the last week.

The system says  “Welcome to Xubuntu 9.10″ in the web page reached with “Applications > Help”, and “Update Manager” says “11.04″ is available, so I think this is the system that was originally installed a s 9.10, and upgraded to 10.04 and 10.10.

There was no way for me to get sound out of this system. Many tweaks and such did not help. Windows runs sound fine.

I looked to see if I installed anything recently, and “Synaptic” said I had installed jackd – way back in October. I uninstalled jackd, and now I can output sound. I am able to record from a USB webcam, but Pinyinpro.com won’t use it.

One thing at a time.

Gui is cute, and sometimes productive, but GNU command line saved my sanity today.

Tortoise is a good GUI for using Subversion on Windows. It nicely flags all the files with status symbols on their icons.

Usually.

Sometimes it gets confused when a change is made 2 or more folders deeper, below the one on display. I don’t know whose cache is causing this – Microsoft’s or Tortoise’s, but it’s a minor issue.

It’s been worse since I upgraded to Tortoise 1.7.5. I jumped from 1.6.x to 1.7.5 the other day while writing docs for some tech writers, including how to install Tortoise.

I have several checkouts (OK, working copies) from the same corporate repository, all checked out in C:\svn. (OK, creativity didn’t seem necessary in this case, OK?)

Today the checkout I am most interested in was mostly not displaying its status icons. Yesterday I wasn’t as worried about it. Usually the entire tree was unaccented. Sometimes a folder would light up until I changed something. Then I noticed that all the “.svn” folders were missing, except in the top folder of the tree. Weird. I checked settings on a couple of things to make sure hidden folders were visible. For a while I had a grain of doubt that maybe the .svn folders were really gone.

So I went to the command line. “dir” didn’t see any .svn folders at all. That was because they were “hidden” by a Microsoft flag on them. “dir /ah” showed them, but not any of the other files/folders. Two dir commands required. Painful.

I have GNU Win32 tools installed, which is a port of the regular GNU tools to Windows.

So the answer was “ls -Al”, or “ls -A” for that economical look.

Thanks to all the GNU developers and those who ported and packaged it for Windows. You help me stay sane on the MS platform.

The site to download for Windows is getgnuwin32.sourceforge.net.

Yesterday, I donated blood again.

They have been asking you questions on the computer for the last year or so.
Example: “Have you eaten any pogo sticks in the last 30 days (since 09/01/2012)?”
The accompanying voice asks without telling you what the date was a month ago, fortunately. It was enough of a distraction that they used a different reader or a different room when they added new questions; a computer generated voice would have been actually irritating.

So there was the date, to me it meant Sept 1, and my fast read of it ignored the year which would have made that a future date. The fact that I can’t read is hardly relevant here. The real point is that they used numeric dates, which are always ambiguous.

Take this home and tell your friends:
Complain when computers don’t display or print dates with a 4 digit year and a text month that is at least 3 letters long. Maybe we can get a culture going that actually communicates clearly.

And please take any managers you know from Canadian Blood Services to CapCHI meetings on the third Tuesday of the month at The Code Factory. then buy them a beer afterwards at whatever pub we go to.

Have you ever filled out a date field  in DYM or MYD order? Shame on you!

I'll be giving a introductory-level presentation on Urwid at the Python Malaysia February Meetup in two weeks. I'm covering the basics with a short presentation and there should be plenty of time for questions or digging in deeper on any aspect.

[Update 2012-02-04]: Slides now available

[Update 2012-02-06 added some photos]

I decided to look at what blog tools are available in Linux. I want to  use them with my WordPress.com blog, of course, so that is how I tested them.

I have only checked out a couple of tools, but I find them mostly not working very well with WordPress.com. The only one that has worked at all is QTM, so far.

BloGTK

This is the recommended tool for Linux, according to the WordPress site. It won’t install in Oneiric. I expect I could make it work if I fiddled with some settings for apt-get, maybe. But the author is not working on it, so no real desire to try.

gnome-blog

Broken. Intended for Gnome 2. One of the libraries is not compatible with Gnome 3: “python-gnomeapplet”. Maybe there is no concept of applet in Gnome 3?

Drivel

I tried it. Editing a new post worked. There were error messages connecting to WordPress.com. I was not able to post the blog because it could not get permission to write.

QTM

This one was able to post a message, but left the message in the “draft” state on WordPress.com. That may be my fault – there is a “draft/publish” drop down on the app.

Because it was “posted”, it put the file into some sort of archive state, so that the next time I went to edit, I had to fiddle around to be able to see it. Finished editing the post on WordPress.com.

Other options

There is at least one plugin for FireFox for editing blogs. But I was looking for tools for Gnome so I can try out Gnome 3, so I haven’t tried it yet.

The Humble Indie Bundle #4 was nice enough to bring Super Meat Boy and a bunch of other great games to Linux. The SMB people however seem to want to punish you for playing on a keyboard and leave you with SPACE as jump, SHIFT as run, and no way to reconfigure the keys.

Here is a little xmodmap script that makes playing on a keyboard much more enjoyable:

keysym x = space
keysym z = Shift_L

Just save this as xmodmap.meat and then run xmodmap -pke > xmodmap.orig to save your original key settings.

Finally, run xmodmap xmodmap.meat before starting the game, and xmodmap xmodmap.orig when you're done.

Python is a wonderful language, but some parts should really have bright WARNING signs all over them. There are features that just can't be used safely and others are that are useful but people tend to use in the wrong ways.

This is a rough transcript of the talk I gave at my local Python group on November 15, with some of the audience feed back mixed in. Most of this came from hanging around the Python IRC channel, something I highly recommend.

[update 2011-12-19: improved "array" critique, add "python -i" suggestion to "reload" critique, add html targets to sections]

[update 2011-12-20: include additional links from agentultra and ffrinch]

[update 2012-01-06: added hasattr and find]

This release adds the long-requested linear scale feature to Speedometer. You can now also adjust the minimum and maximum values displayed, and switch all units shown to bits per second.

• Speedometer home page
• Download Speedometer 2.8 tarball

Urwid maintenance releases 1.0.1 and 0.9.9.3 are now available. This may be the last 0.9.9 release, users are strongly encouraged to upgrade.

• Urwid Home Page
• Changelog
• Download 1.0.1 Tarball
• Download 0.9.9.3 Tarball

This is a major feature release for Urwid.

• Urwid Home Page
• Download Tarball

Happy 1.0 Urwid! It's been a great nearly-seven years since our first release. Huge thanks to everyone that's contributed code, docs, bug reports and help on the mailing list and IRC.

In any web application user data must be translated from HTML form data to native types and database types, and back again. Django web applcations are no different.

The "right way" to handle custom types is to extend Django's widgets, form fields and model fields. However, understanding exactly how these types perform each step of the conversion can be confusing. This post will attempt to explain how the data is converted at each stage and offer some advice about creating custom widgets, form fields and model fields.

This article is based on Django 1.3 and assumes the reader has experience creating and using Django forms, models and validation.

This is a maintenance release that fixes a number of bugs that have been found in 0.9.9.1.

• Urwid Home Page
• Download Tarball

I set up a VM to present software to a client remotely, but I needed a way to record both the audio in and out so that I could capture both my presentation and the client's questions. In the past I've used some ALSA configuration magic for audio things advanced enough that they don't have a friendly GUI, but since Pulse Audio is the shiny new thing I decided to go that route.

It turns out to be fairly simple. I create a new null sink (think: fake sound card for output) and attach a loopback from the audio out monitor of the "real" sound card and another from the the audio in of the "real" sound card:

pactl load-module module-null-sink sink_name=bothsides
pactl load-module module-loopback latency_msec=5 sink=bothsides \
      source=alsa_output.pci-0000_00_04.0.analog-stereo.monitor
pactl load-module module-loopback latency_msec=5 sink=bothsides

The alsa_output... source comes from running pactl list and copying the device name. The second loopback automatically uses the only alsa_input... source device. Then I can record from the monitor of this null sink with a command like:

pacat --record -d 2 | sox -t raw -r 44100 -s -L -b 16 -c2 - "recording.wav"

The -d 2 option selects the new null sink monitor device I created (the index may be different in your case). Last, you may want to use the pavucontrol program to adjust the levels for the input and output so you don't end up with one sounding much louder than the other in the combined recording.

Here are the slides from my Python talk at OLS this afternoon.

Ottawa Python Authors Group meeting tomorrow Thursday May 26 at 8p.m. Best of all it's not me talking this time!

Hope you can make it out.

Among the features announced with the release of version 4.6 of the KDE Software Compilation is KateSQL, a SQL Query plugin for the Kate text editor providing the basic functionality of a SQL client. It leverages the Qt SQL module, allowing you to make a connection to most types of databases. Out of the box [...]

Catching up on some more old business: here are the slides from the Python 2 and Python 3 talk I gave at last month's OCLUG meeting.

I am also preparing some Python tutorials for the upcoming 2011 Linux Symposium in Ottawa June 13-15. Hope you can make it.

I'm late with this update (busy catching up on other work that I neglected last month) but I must report that the Ottawa IPv6 Summit went far better than I had hoped: Great turn-out, great venue, great talks and great food.

Pictures are now available from Richard Guy Briggs and we're working on putting the talk videos online with the help of ISI Global Webcasting.

The space at Telfer School of Management was ideal, and the Telfer volunteers got everyone registered helped everything run really smoothly all day.

It was tons of work, but I look forward to doing it again. Maybe I'll even catch more than a couple talks in person next time.

Just a reminder that tomorrow is the last day for the early registration discount.

The preliminary schedule has been posted. Register now!

I will be giving a talk on Python 2 and Python 3 at the Ottawa Canada Linux Users Group meeting on Tuesday. Hope to see you there.