I could talk about aesthetics; I could talk about line noise andreadability; but for me it ultimately comes down to one thing: datastructures.

Namely, I find it very hard to write perl code of any depth withoutrunning headlong into the fact that Perl's 'collection' types (arraysand hashes) can't contain themselves. All they can contain is scalars(strings, numbers, and references).

For example, recently I was writing a program to mass-query the SBLDNS blocklist

Python has recently (at least for some values of recently) grown 'list comprehensions' ,which let you easily iterate over a list to transform or selectentries (or both). List comprehensions can be thought of as syntacticsugar for map and filter operations, but they're actually morepowerful.

One reason is that you can write a multilevel list comprehension,which effectively iterates over multiple levels of lists. Take thecase where you have a list within a list and want to return all of thelow-

This is roughly speaking a table showing the top N SBL listings thatare spamming us over the past 28 and change days. I generated it bygrabbing all rejected IP addresses, looking them up in the SBL, andcounting how many hits each SBL listing accumulated.

The spam storm seems to have died down nowand it's a Saturday night, so time for a wrapup and a look at theoverall stats this week.

This week's total is 295,000 SMTP connections from at least 38,000different IP addresses. In hindsight, the spam storm was probablyalready dying on the 26th, since we got only about another 60,000 SMTPconnections since then (which is more or less average)

As a companion to PythonDNSQueries , here is the sameprogram to query the SBL in perl, using the CPAN Net::DNS package.

#!/usr/bin/perl -wuse strict;use Net::DNS;my $sstr = ".sbl.spamhaus.org";my $res = Net::DNS::Resolver->new;foreach my $ip (@ARGV) {	$ip = join('.', reverse(split(/\./