Python

One of the unquestioned assumptions behind object-oriented programming is that objects are instances of a class, and thus implicitly stay that way. This is akin to the philosophical concept of nature, as in an invariant quality of something, that cannot be changed:

But is there any one thus intended by nature to be a slave, and for whom such a condition is expedient and right, or rather is not all slavery a violation of nature?

There is no difficulty in answering this question, on grounds both of reason and of fact. For that some should rule and others be ruled is a thing not only necessary, but expedient; from the hour of their birth, some are marked out for subjection, others for rule.

…

Again, the male is by nature superior, and the female inferior; and the one rules, and the other is ruled; this principle, of necessity, extends to all mankind.

…

It is clear, then, that some men are by nature free, and others slaves, and that for these latter slavery is both expedient and right.

Aristotle, Politics I, 5 (emphasis mine)

Needless to say, this concept is reactionary. One may well object that given slavery’s omnipresence in antiquity, even a great philosopher such as Aristotle could not be entirely free of the prejudices of his time. This conveniently ignores the fact Aristotle was a pupil of Plato, himself a disgruntled aristocrat who collaborated with Spartans when they overthrew Athenian democracy after the Peloponnesian war, and is arguably one of the theoretical founders of the totalitarian state. I would say it is rather the presumed greatness of Aristotle that should be reexamined, but I digress. For more on this subject, read Karl Popper’s The Open Society and its Enemies – Volume 1, The Spell of Plato.

Thus, OOP carries within it the conservatism of Plato and Aristotle, people who resented how the young Athenian democracy had usurped the aristocracy’s natural (in their eyes) right to rule over others. This is not just an academic consideration. Computer programmers influence society, specially those who work for governmental information systems, and if you consider the Sapir-Whorf hypothesis, the language they use affects the way they think.

This is why I like Python’s ability to morph an object from one class to another:

Python 2.2.1 (#1, Apr 18 2002, 13:06:27)
[GCC 2.95.3 20010315 (release)] on sunos5
Type "help", "copyright", "credits" or "license" for more information.
>>> class Slave:
...     def whip(self):
...             return 'Yes, master'
...
>>> class Freeman:
...     def whip(self):
...             return 'Die, fascist scum!'
...
>>> man = Slave()
>>> man.whip()
'Yes, master'
>>> man.__class__ = Freeman
>>> man.whip()
'Die, fascist scum!'

Most modern PCs and Macintoshes feature Wake-on-LAN. This feature, originally called “Magic packet” (PDF) by AMD, allows you to start a PC remotely by sending a specially formed “magic packet” to its Ethernet interface. On Macs running OS X, Wake-on-LAN seems to work only when the Mac is in sleep mode, not when it is completely turned off. The original intent was to allow administrators to boot PCs remotely to run backups, but with the spread of DSL, there are other uses.

For instance, I have a low-noise Solaris machine running 24/7 at my home (angband.majid.fm), and when I need to access my (noisy) home PC, I just log on to that machine via SSH, wake up the PC and then log on remotely using pcAnywhere. The same works with my iMac G4

Here is a very simple Python script that starts a machine with a given MAC address:

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.sendto('\xff'*6 + '\x00\x02\xb3\x07\xb6\xd1'*16, ('192.168.1.255', 80))

It will start the machine with MAC address 00:02:B3:07:B6:D1 on the subnet 192.168.1/24 by sending a Wake-on-LAN magic packet to the subnet-directed broadcast IP address.

Update (2003-12-05):

Now that you have woken your Mac, how do you send it back to sleep? Read this article to find out.

Update (2006-03-19):

On certain versions of Linux, you may get a “permission denied” error message because you are trying to send a packet to a broadcast address. The following code should work:

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
s.sendto('\xff'*6 + '\x00\x02\xb3\x07\xb6\xd1'*16, ('192.168.1.255', 80))

Patrick Ball is the author of a book called Making the Case describing how information technology and notably databases of human rights abuse reports can yield statistical evidence of wrongdoing by specific individuals (say, policemen).

He testified at Slobodan Milosevic’s trial in The Hague. Apparently, the processing was done in Python, see page 2 of this Wired article for more details.

I found this interesting weblog on the subject, and a tool to use  Python IDE.