Archive | March 25, 2007

An even dozen people showed up for the Python Special Interest Groups March meeting, held as usual at the Amoskeag Business Incubator in Manchester, NH.

Bill Sconce called us to order promptly at 7 PM and we proceeded through the printed agenda. It was duly noted the Ben Scott deserved heckling despite his absence. We ran through announcements of a couple of upcoming meetings, plugging the MythTV installfest beta and pointing out Jarod’s book. We mentioned meetings upcoming for the LUGs, including ZFS at DLSLUG, LVM at CentraLUG and the new Ruby group.

Kent’s Korner: Kent S. Johnson presented his month talk, this month on list comprehensions. Kent had a great handout, and has collected his past couple of handouts in one place. Starting with simple examples and building in complexity, Kent lead us through what can be an intimidating topic in a way most couple follow. Some great discussions, on-topic and off-, regarding assignment and Python idioms, always make this a fun part of the meeting.

There was some discussion of Python 3000 and its expected schedule. Bill Sconce had a video of Guido practicing his Py3K presentation in front of an audience at Google, which he went on to present at PyCon.

For the Gotcha of the month, Bill Freeman offered up an “Un-Gotcha:” a=b=4 works, but not for the reason you might think. Assignments of this style in C have a different underlying meaning, and perhaps in some circumstances, different side effects. A key to understanding the single = assignment in Python is to understand that it is a STATEMENT. There is no value associated with the statement and “chained” assignments in Python like the above are specially-coded as an exception case. This lead to yet another great discussion.

Ric Werme showed off the web pages that result from his Python software that collects and forwards weather data from his weather station. His current conditions page, http://home.comcast.net/~ewerme/wx/current.html has links to everything else. Ric bought the weather station in part to have an excuse to write more Python code, and his current code runs the gamut from implementing the weather station protocol through pyserial.py and the serial port to CGI scripts that take data requests, fetches the data from MySQL, creates gnuplot data files that create .gif files, and returns a HTML page to display the results. His description of the software is at http://werme.8m.net/wx/vantage_software.html .

Ric also demonstrated a Python cgi script for collecting data for a weather observers group that Todd Gross created while he was WHDH. It’s customizable, so people can create a form preloaded with their location that offer just the data they collect, and the submission code adds it to a MySQL database and recreates a web page of members reports over the previous day.

Shawn O’Shea showed off Python running in the Win32 and COM environments. Shawn does a lot of work administering and automating Windows configurations, and the COM set of interfaces can allow a lot of internal manipulation of the major applications, a big step up from the VBScripts supplied by Microsoft with some of the tools. Shawn demonstrated the canonical Hello, World with Microsoft Word, but then dug into a couple more concrete and practical examples with querying the Registry and spelunking in the IIS metabase.

Lots of interesting stuff coming up at future meetings: Martin Ledoux offered to show something on the work he’s done with amateur book-binding with pytut/pyref books. Kent has promised an update soon on his real-life experiences with Django. Ray Côté may be able to show off the new web site he used as an excuse to miss the meeting. And I’ll bet Bill will wheedle some more cookies from Janet.

Thanks to Bill Sconce for organizing, Alex Hewitt for getting the networking working, the Amoskeag Business Incubator for providing the great facilities, Janet for the awesome cookies, Kent for his great Korner, Bill Freeman for the csv module and those strange blinking white blocks, Ric Werme for demoing his weather projects, Shawn for the Win32-COM-Automation and everyone for attending and participating.

P.S. Anyone got python running on a WRT54G?

P.P.S. Tom Mosco mentioned to me that the Chicago Python group had a very long presentation on Django by the creators and also a Ruby on Rails presentation by its author. Videos can be found at here and here