new and improved sqlWrap.py

After reading the Python Cookbook and attending PyCon, I have enormously improved sqlWrap.py, my Python module for handling DB-API 2.0 connections conveniently.

Also at PyCon, I learned that I could be accused of having duplicated projects like

• ll-orasql
• db_row
• dtuple

Like them, I allow tuple-like, dict-like, and object-like access to fields. I like mine better, though; it requires less preparation, and has really nice reporting methods. For example,

conn = sqlWrap.SqliteConnection('myDb.sqlite')
print conn.select('myTable').xml()

... is all you need to get an XML report on myTable. Similar reporting methods exist for

• tables in pp (prettyprint), xhtml, ReStructured Text
• transposed tables in pp, xhtml, ReStructuredText
• SQL INSERT statements

Hey, if everybody gets to write their own web app platform, why shouldn't I write my own DB-API wrapper?

PyCon2006

No, Guido doesn't know I have this... I snagged it from the badge reuse box. You keep your smelly old rock star T-shirts, I'm keeping this.

So... PyCon. Wow. It was wonderful, of course. What else could it be? Put 400 people with that much intelligence, creativity, and energy in one place, and it can hardly help but be wonderful.

What surprised me is that I found so many good ideas no matter what I was doing at PyCon. Whether I was in a talk that I expected to benefit hugely from, or a "Probably useless but I guess I'll go anyway" talk, or just chatting between or after sessions, I seemed to learn good stuff constantly just the same. The serendipity was worth more than the "planned" learning, and maybe that's what makes conventions so much more useful than formal books and classes and so forth.

Python Cookbook

This may seem silly, but I really have to sing the praises of the Python Cookbook, 2nd Edition. Everybody else has known about it forever, but I just got my copy a month ago.

I am blown away. I can't believe how good this book is, far beyond any other programming book I've ever known. I'm now completely embarrassed about the quality of the code I wrote without it, and tempted to stay up all night refactoring everything. In fact, I've already largely rewritten sqlWrap.py based on what I've learned.

I'm afraid I dawdled about buying my copy because I never found the recipes at ActiveState all that compelling - occasionally nice, but usually nothing to jump and scream about. I figured the Cookbook would just be a bunch of them, bound together. Not so - the careful selection and excellent discussion make it amazing. It's like having a master programmer at your elbow to guide you.

The Geek Event Aggregator is ready!

The Geek Event Aggregator is more-or-less ready for prime time! It now collects many more events. Better yet, it is very easy to feed more event sources, so it is set for even more growth. In other words,

PLEASE FEED THE AGGREGATOR NEW SITE SUGGESTIONS!

Some design notes:

After fooling around with complex regular expressions, Beautiful Soup, etc., I found a quick-and-dirty way that works better. The Aggregator downloads a page's HTML, replaces all tags with carriage returns, breaks the remaining text into lines, and checks those lines for ones that appear to contain recognizable future dates. The Aggregator assumes that is an upcoming event date. (There are many reasons dates get put on websites, but future dates almost always refer to meetings or events.)

Wow, human beings have many, many, many ways to write dates. Fortunately, python's dateutil module can recognize most of them - I mainly have to modify that to avoid false hits (like interpreting '.' as 'today', or '2006' alone as 'Jan 1, 2006').

Some sites already aggregate events from several groups and places together; for those, the Aggregator uses a slightly different algorithm. It finds the dates as above, then finds the location and event name by their line-number position relative to the date. (A human being (me) needs to provide relative line-number positions for those values in advance; for instance, one site may always list location on the line immediately after the event date, and that fact is recorded in advance.)

For the multi-event sites, the Aggregator has a decent but kludgey algorithm to parse city and region, despite the great variety of ways to write a location. Part of that relies on a list of recognized city names. It can be used for the single-event sites, too; if a recognizable city name is in the site's Title, or in the text in the form "Blah Blah City Blah Blahware Group", the Aggregator can find it. But if your event is in Athens, GA, the Aggregator thinks it's in Greece.

HTML DB makes it very convenient to build a web interface to the data. Oracle is also very gracious to host a free sandbox for HTML DB projects (which is where the Aggregator lives right now.) Unfortunately, as far as I can see, HTML DB doesn't support RESTful interfaces, or serving up pages as XML. That's a pity, because this cries out to be a REST web service. Maybe eventually I'll buy/find a place to host the web app in TurboGears or something.

For now, I've given up on feeding upcoming.org. Upcoming mandates an actual street address, which is just too hard to find automatically. I'd still like to pull from it, although I'll have to check their legal requirements, and - dare I say it? - I don't know if it will really have many relevant events I don't already have.

I'm sorry the events are so U.S./Canada-centric. It only has a handful of events from elsewhere, and it doesn't break down regions within other countries. (What's wrong with going from St. Petersburg to Novosibirsk for a meeting, anyway? Isn't that what the Trans-Siberian Railway is for?) You can help fix this by suggesting new sites to scan, and volunteering to introduce regional granularity for other countries.

Actually, because I've been the only one to feed the Aggregator so far, the events are Ohio-centric. You folks in benighted backwaters like California and New York are just going to have to feed it your own favorite sites if you want to fix that.

Some of the many things that produce misses and false hits:

• Dates without years. Somebody puts on the website, "Our next meeting is Nov. 19." The Aggregator can't tell that they haven't updated the site since 2004.
• Years must be on the same line as the rest of the date. If you say,
  2005 events:
  Feb. 14
  Aug. 12
  ... the Aggregator doesn't see the "2005", and believes there are events on Feb. 14 and Aug 12 of this year.
• Frames. Well, you can't blame it; frames mess up everybody. But if you can dig into the HTML source and puzzle out the URL of the frame with the data, then that can be read. That's what I did for the OKCOUG webpage, for example.

Geek Event Aggregator's future

The strangest thing happened to me this morning. The clouds split open, and a beam of light shone down onto me. (Since I was sitting in my cubicle, this in itself was odd enough.) A Voice spoke from Heaven, and said,

"Catherine, remember that somewhat cheesy Geek Event Aggregator you put on HTML DB a while ago?"

"Yes, Lord?" I said. (That seemed like the obvious response. That the Almighty would speak with hyperlinks didn't seem too surprising.)

"Well, I have heard the cries of my people. I want you to rewrite your aggregator to both consume and provide events in iCalendar format. Also, interface it with upcoming.org - both to download and to upload. Behold, Python libraries for upcoming.org have already been written for you. And I'm thinking that Beautiful Soup might help you pluck event descriptions from the God-awful HTML jungles you find them in."

"It sounds wonderful, Lord," I said. "But when am I supposed to do this? I mean, you did just drop custody of our Godson into our lap. Time is not exactly abundant right now."

There was a long pause, then the Voice said, "Let me get back to you on that."

cleanPath executable ready

An executable version of cleanPath is now available here!

You do need .NET Framework 2.0 to run this. It's pretty painless to download and install. You don't need IronPython.

Thanks to the newest IronPython release for making this possible! When I run

ironpythonconsole cleanPath.py

, the code runs, and it also generates cleanPath.exe without even being asked to. Until now, though, that .exe didn't actually work. In IronPython 1.0 Beta 2, however, released just Wednesday, it works great! I do need to put IronPython.dll in my directory before I compile... other than that, it's so simple, even a DBA can do it.

cleanPath.py: an IronPython utility

During my CodeCamp presentation, I introduced a very sketchy (and logically flawed) script to examine a PATH environment variable and clean out unwanted elements.

Since then, I created a much-improved version in IronPython which, I think, is actually worth using. Features:

• Conveniently view and delete path items
• Nonexistent directories and duplicate items are flagged, and can be purged with one keystroke
• works on PATH, CLASSPATH, PYTHONPATH, PERL5LIB, etc.

It's Windows-only, but only Windows makes editing your PATH such a pain, anyway.

The code is here.

Right now, you need IronPython, and use "ironpythonconsole cleanPath.py" to run it. I need to figure out how to generate an .exe, since getting set up with IronPython is too much to ask just to clean up your PATH.

[EDIT: An executable is ready now. See my next blog entry.]

Smurfette syndrome

One thing about the CodeCamp, though: severe Smurfette syndrome. Maybe 10% of the attendees were women, but probably closer to 5%.

I don't think it's the CodeCamp's fault; I'm afraid they may have gotten an accurate sample of the programmers in the area, and that's the scary thought. Possibly things would have been a little better on a weekday; men might feel more comfortable in taking a day away from home duties for their professional development. Still.

I know, it's been talked to death, and there are a million theories and stuff, but... yikes. It's just scary that one year goes by after another, and the situation persists.

On the other hand, the GCOUG meeting was about half women, maybe even a majority. At a small meeting, granted, but it's still a bright spot.

Dayton-Cincinnati Code Camp review

If you missed the CodeCamp, don't miss the next one. It was great. I'm not even into .NET, but even the minority of the conference that was non-.NET was well worth my time. Plus, sampling a bit of the .NET take on a few topics was good for my general education.

I almost wish I were involved in .NET, purely for the sake of the Dayton .NET group, which has a vitality that you just don't see that much of in the Dayton area IT community (at least, in my tracks thereof.)

Anyway, a few things I learned...

• There really are Python-experienced people in the area; I'd just never found them before.
• Ruby on Rails supports Oracle. Uh-oh. It's not that I'm unwilling to learn Ruby; it sounds great, and (of course) simple to learn. It's just that I really want to use TurboGears, but it uses SQLObject, and Oracle support in SQLObject is the sword in the stone. Many have tugged, but none have completed it, and maybe I should stop waiting and just use RoR for now.
• Speaking of Ruby, never miss seeing Jim Weirich speak. I already knew that, but maybe you didn't.
• GCOUG really needs to work on getting more people involved. There were 15-20 people at Jimmy Brock's talk on Oracle Developer Tools for .NET - none of whom had more than the haziest awareness of GCOUG's existence.
• Speaking of Jimmy's talk, Oracle Developer Tools has a great and handy way to bring .NET assemblies from Visual Studio all the way into Oracle, where they can be used like stored procedures.
  So, one glorious day, this year I hope, Visual Studio will support IronPython, and I'll be able to (essentially) write my Oracle stored procedures in Python instead of PL/SQL. And choirs of angels will sing.

I'm sure I'll have more to say about the Camp as I think about it.

Presenting (with) Bruce

When I present at a meeting, I like to use plenty of live demos. I can get away with this, because I type very, very well. (I did get into IT via the secretarial pool, after all.) Still, even I get a little nervous about whether I can keep up typing speed and accuracy with the pressure of a whole audience staring at me.

Fortunately, This blog post by Andy Todd (You do read his blog, don't you?) pointed me to Bruce, a wonderful presentation tool freshly created by Richard Jones.

Bruce lets you wrap up decent-looking slides, graphics, and Python interpreter sessions all into a single presentation that scrolls smoothly along at your command. (Simply being spared the fuss of flipping between Presentation slides and a command-prompt window is a blessing.) For demos, you can pre-enter the text you want to type, then Bruce sends it to the interpreter one character at a time. You type 'dfjkasfjdska;dfsafd', but 'def plusOne(x): return x+1' appears on the screen, and the audience thinks you're a keyboard goddess.

My one disappointment in Bruce - as I understand it (I just found it, you know) - is that the wonderful interactive session can only be used with a Python session. I'll need to dig into Bruce and PyGame to verify that, and to see if it can be extended elsewhere. I dearly want to use it when I'm demonstrating SQL.

Until Bruce, incidentally, my best bet was TPP, the Text Presentation Program. I've seen presentations done with it, and it looks OK, except it's written in Ruby and has dependencies (ncurses) that need C compiling - not very practical where I am, unfortunately.

Search engines are not Zen

I decided that I should make myself a list of questions I've never been able to resolve, or that were very difficult to research, because they don't "search" well. That is, in everything from Metalink's Search bar to Google, it's hard to come up with relevant results.

For instance,

- I'm trying to use RMAN DUPLICATE, and it does indeed produce the data files on the auxiliary database, but it doesn't create a controlfile. The documentation clearly says it should. Searching on terms like RMAN DUPLICATE controlfile not generated only brings up more pages saying that it should.

- All sorts of questions like such-and-such service DOESN'T start, program WON'T run, logfile ISN'T created. Negation - "not" - is clearly a failing of a typical search. Searching for green eggs no ham will find you 10,000 pages on green eggs AND ham, with the one page on "My green eggs came without ham!" buried anonymously as result #4,312.

I'm not sure what I'll ultimately want to do with this list. But I began to wonder, more broadly, if someone out there had already started assembling issues of unsearchable questions. Ironically, Can't Find On Google is very easy to find on Google.

Dayton - Cincinnati Code Camp

Hooray! - to the Dayton .NET Developers Group for putting together the Code Camp on Jan. 21, 2006 - a whole day of community-provided seminars on a variety of programming topics. For free! I'm looking forward to it; in fact, I'm planning to present there (on Python, naturally).

If you're anywhere near southwest Ohio, come and enjoy. Better yet, come and share! Whatever cool programming tricks you have up your sleeve - come and show the rest of us!

LibraryLookup published

My article on LibraryLookup has been published in the October 2005 issue of Technology First, a tech newsletter for the Dayton area. (I'm on p. 8-9). (The print article's content ties in with this blog post)

The sixty-second version: LibraryLookup lets you query your library's catalog directly from a page of a book vendor like Amazon, looking up that particular book for you automatically with just one click. You can get it installed in your browser in, oh, about five seconds. It's really cool, not just for helping you find books, but also as an example of clever and sneaky use of JavaScript.

Why do almost all contracts and job postings specify exactly the software that they want you to use (or to have used)?

When they want to incorporate you tightly into a large project that has already gotten underway with some specific software, OK. But I think such over-specifying is also the custom in cases where that is not at all true. It's very annoying to somebody like me, who bizzarely imagines she might be able to select the best tools for her own work.

When I take my car to the mechanic, I don't say, "You must do all the work using a Sears Craftsman #3 box wrench." But maybe, if I were a writer of contracts, I would.

Announcing Dayton-Oracle mailing list

Q. How do Dayton-area users of Oracle stay in touch with one another and find out what's going on in their community?
A. They don't.

Q. Well, that's lame. What can we do about that?
A. You can sign up for the Dayton-Oracle mailing list I just set up at FreeLists.

Please spread the word!

cx_Oracle and Ubuntu

Naturally, after getting Oracle working, my next move was to get it Python-powered by installing cx_Oracle. Installation seemed to go OK, but when I tried to use it...

>>> import cx_Oracle
Traceback (most recent call last):
  File "", line 1, in ?
ImportError: libclntsh.so.10.1: cannot open shared object file: No such file or directory

which seemed odd, because

catherine@ubuntu:~$ locate libclntsh.so.10.1
/app/oracle/oracle/product/10.2.0/db_1/lib/libclntsh.so.10.1

I extrapolated a solution from an old mailing-list post by Karl Putland: I appended /app/oracle/oracle/product/10.2.0/db_1/lib to /etc/ld.so.conf and ran ldconfig.

That was the only trick - it's working fine now!

Oracle on Ubuntu

I love my new Ubuntu Linux (version 5.10). I love how easy it was to install, how it picked right up on my wireless card.

Oracle doesn't support Ubuntu, but I installed it anyway and it's doing fine. The process was tricky, though. Here's what I learned.

1. RTFM. The Installation Guide is very important, more so than when installing Oracle on Windows. It has to be the primary document you work from, and follow step-by-step. Any other advice on Oracle/Ubuntu that you may Google up is secondary. Where Red Hat and SuSE directions differ, follow the Red Hat ones.
2. This document is useful primarily for reassuring you that the error messages you get are OK.
3. Make sure the Universe is in your Synaptic repository and install these packages: gcc, make, libxp, libaio, lesstif2, lesstif2-dev, rpm, and libdb1.
4. You can't find all the packages that the install documents call for in the Ubuntu Universe. That seems to be OK; just find the ones you can.
5. The magic word is runInstaller -ignoreSysPrereqs.
6. One little misstep and you may get something broken. It took me a couple attempts. Try, try again, following that Installation Guide even more carefully.

Oracle - Python wish list

For my upcoming Oracle - Python talks at OOUG and (maybe) COLLABORATE 06, I want to write a nice Python script in realtime, before the very eyes of the audience, like a cooking show hostess would. I'm having trouble deciding on an objective for the script, though. The ideal script would make Oracle people sit up and scream, "I want that! That power must be mine!" It should also

• Be very Oracle relevant
• Be something that can't be done with SQL or PL/SQL alone
• But still use some SQL (to demonstrate cx_Oracle)
• Not duplicate the function of any existing Oracle utility or Oracle Enterprise Manager (this one worries me since I don't even know everything OEM can do)
• Be writeable within an hour (shouldn't be a problem)

I'm brainstorming for ideas, but I don't know if any of them are really "it".

• Compare parameters in INIT.ORA to live database (this is what I used for my paper)
• Condense or groom a TKPROF output file
• Populate a database table from a website (but what website? What's cool enough?)
• Find and compare TNSNAMES.ORA files scattered across filesystem. Find TNSNAMES entries that are "dead" (unpingable).
• Format alert.ora for better readability; color-code messages?
• Measure log switch frequency from alert.ora
• Find obsolete (unused) configuration files like init.ora, ORACLE_HOMEs, etc.
• Clean up PATH (mine gets cluttered with droppings from various installs/uninstalls)

Any comments on these? Anything you'd like to put on the wish list? Let your imagination run wild - what wishes would you make to a magic Oracle genie? That's the kind of "gotta have it" feeling I'd like to produce.

Ohio LinuxFest

I had a great time at Ohio LinuxFest. Highlights, in my book, were

• Jorge Castro's Ubuntu talk. He pointed us to a lot of great stuff to try out, and his enthusiasm was infectuous.
• Rich Bowen's mod_rewrite talk. I've never encountered Apache documentation that I was truly happy with, but Rich was wonderfully clear. I want his book.
• Ram Rao's virtualization talk. Xen sounds like it has jumped straight to #1 in my List of Reasons My Management Would Let Me Use Linux For The Database Server If They Had A Clue. Moving entire virtual machines easily between production and development servers, with almost no performance impact... wow, that would be incredible.
• The reception. Hey, the only thing better than dancing is dancing with geeks. Too bad I had to leave early, but somebody foolishly located Dayton too far from Columbus.

I heard that the attendance had more than doubled from the last year, and indeed, many of the people I talked to were quite new to Linux. That's the one improvement I'd suggest for the event. There were good talks for newbies, but not enough of them, nor did the schedule provide clear enough guidance to help newbies steer themselves that way.

COLLABORATE 06, featuring me, maybe

I just submitted a proposal for a technical session ("Python and Oracle: Coding that Cooks") at COLLABORATE 06, the IOUG's conference next April. Wish me luck! I'm not sure how hard it is to get a slot; I do know that the speaker quality there has been excellent for the past two years.