One of the neat things about programming in Python is finding out aboutclever little idioms that are obvious in retrospect. My latest find isa little trick for handling mutable function arguments.

As I mentioned back when discussing the consequences of def beingan executable statement , the way I'd beenhandling mutable default arguments was something like:

def foo(a, blst = None):  if blst is None:    blst = []

At two lines, this is just verbose enough to grate lightly butirritatingly on my nerves

In a comment on the last entry Imumbled yet again how I was annoyed that Python doesn't have anequivalent of C's '? :' conditional expression operator. Thensome neurons in the back of my mind woke up and asked 'didn'tGuido van Rossum say he was going to add this to Python 2.5 ?'

In the process of trying to figure out if thiswas still happening (it is), I read this message (via here )and found out about a

Vendors, I have a simple request for you: give me an RSS feed foryour security fixes and system updates . No, please don't suggest thatI subscribe to your email announcement list, because these days emailis just too much of a hassle. Accept it; RSS is the new lightweightnotification format, and notification of new updates is just what Iwant.

And don't just give us one global RSS feed of everything. Be modern; letpeople get narrow feeds as well as broad ones

I spent part of Monday poking through a Fedora Core system that hadbeen partially compromised, and I was reminded yet again how one of myfavorite RPM features isn't as widely known as it could be. Namely, thatRPM keeps a handy database of the MD5 checksums about every file it'sinstalled (as well as a pile of other information). The rpm command's -V option taps this database to verify the actual files on the systemagainst what the database says they should be and

Every so often I read a genuinely electrifying article, one that makesme sit bolt upright in an 'ah-ha!' moment as it crystallizes things I'vebeen stumbling towards.

Peter Drucker's The Five Deadly Business Sins is one such article. Go read it now; I'll wait. (It nailed me to thefloor so much that I have a copy saved in case the Wall Street Journalever removes it or moves it behind their pay-wall.)

Looking back over my entries

In the spirit of equal opportunity annoyance :

One of the things that never fails to irritate me with Red Hat is thatwhen you do ' /bin/su root ' on astock system, you get a shell whose $PATH doesn't include /sbin or /usr/sbin .

This trips me up all the time, and every time it's an nngh moment. Andit's not as if Red Hat doesn't already have a ~root/.bashrc that doesquite a lot

My problem with benchmarking is that it's tedious (and finicky). Goodbenchmarking mostly consists of twiddling my thumbs while my tests run,often yet again after some minor tweak or improvement or additionalcase. I can kill days running tests and staring at numbers and not reallyget anywhere (and sometimes I've had to).

All that said, after my entry on some regular expression performancesurprises , I got curious enoughto do more detailed micro-benchmarking. With Daniel Martin 's assistance I was

Irony is a Referer spammer spamming my entryon how affiliate marketing is undead forsomething that sure looks like an affiliate marketing scheme. More ironyis that this is the first Referer spammer in a donkey's age; all the oldones seem to have given up months ago.

This just goes to show that I can find amusing things from readingmy server logs.

An analysis of the spammer

The spammer came from 217.15.96.18, an unremarkable DataStreamMalta IP address that

Now that I've automated almostall of the Hotmail spam report, of course it turns out we've had a quietweek, even more so than last week :

• no messages accepted.
• 22 messages rejected because they came from non-Hotmail emailaddresses.
• 54 messages sent to our spamtraps.
• 13 messages refused because their sender addresses had already hitour spamtraps.
• 5 messages refused due to their origin IP address (one in theSBL, one in the CBL, one from Nigeria, one from