Vitanuova for 2003 October 30

Guido

I went to Stanford with some of my EFF colleagues to hear Guido van Rossum speak. He was apparently your architypical "I am just a nice guy who happened to create a major part of the world's IT infrastructure" sort. (Andrew Tridgell also comes to mind in this capacity.)

I had actually heard Guido speak at a Linux event sometime around 1999, before I became a Python programmer. At that time, people kept asking him why there was a string module rather than having strings be objects with methods to perform common string operations.

Of course, that eventually got changed:

[schoen@zork(~)] python1.5
Python 1.5.2 (#0, Jul  5 2003, 11:45:08)  [GCC 3.3.1 20030626 (Debian prerelease)] on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> dir("foo")
[]
>>>
[schoen@zork(~)] python2.3
Python 2.3.2 (#2, Oct  6 2003, 08:02:06)
[GCC 3.3.2 20030908 (Debian prerelease)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> dir("foo")
['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__getslice__', '__gt__', '__hash__', '__init__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__str__', 'capitalize', 'center', 'count', 'decode', 'encode', 'endswith', 'expandtabs', 'find', 'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'replace', 'rfind', 'rindex', 'rjust', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']

What's more, the string module (in which you find all these functions in Python 1.5) has been deprecated and is slated to be removed entirely in Python 3.0. So I guess the people at that old talk got their wish!

Anyway, when I heard Guido speak in 1999, I had little or no idea what he was talking about. All I knew was that Python was a language many of my friends were getting interested in, and this guy was responsible for it. This time around, I was an actual Python programmer. I found the substance of Guido's talk quite clear and helpful. Among other things, he spent a good deal of time explaining the motivation for and implementation of generators.

A generator is a Python function that uses the "yield" statment. (Well, technically it's the object returned by calling such a function.) It allows you, in a succint way, to write a function with a complicated internal state that returns values sequentially in such a way that they can be used by another complicated function. Without generators, you would probably need to have a complicated data structure to save state in order to switch back and forth constantly between the complicated function and the thing it's callig. With generators, Python saves that state for you. Of course, Lisps had something like this first.

I haven't thought of a non-trivial application for generators, but maybe I would if I were writing some non-trivial programs. (All the things written about generators use parsers as a sample application, but as it happens I never seem to write any parsers...)

It's fun to have the language implementer himself explain language features to you!

Leonard

Leonard is going to Arkansas to work for Wesley Clark. He decided to do this pretty suddenly. I once thought of moving abruptly all the way across the country to do some work, but I decided against it (not being, apparently, so courageous as Leonard).

I wish Leonard all the best for his experience in Arkansas.

Book

I am apparently likely to write a book. The prospect of writing a book seems very exciting to me, although I think the idea that something I write can be a real book (publisher, ISBN, LOC record, binding, in libraries and bookstores, doncha know) is still very foreign to me and may continue to be foreign until it actually happens.

I recently met with a bookstore owner and a publisher who are both really excited about what they do. (The bookstore owner is, by her own admission, particularly insane because she is selling only new books. Of course, all new book dealers' inventory is essentially the same in the sense that they all can order any book in print at the same price through the same wholesalers. And many of them display essentially the same things in their windows and shops, although there is some small room for creativity there. Used bookdealers at least have unique and widely varying inventory and ability to obtain particular titles.) It's really encouraging to me to find that people are still excited about these businesses.

Both publishing and book retailing have become extraordinarily concentrated. (Remember "media concentration"?) Despite many obstacles, and many economic challenges, people are still going into these fields (outside of the giant consolidated firms) and still finding them rewarding and meaningful.

Experience feuding over copyright policy can make us less than respectful of publishers. Entertainment publishers, of course, are our regular villains in the sense that they are constantly engaged in trying to make really bad law. And other people have criticized them on many other grounds than copyright. (Oddly enough, copyright hardly came up in the debate over the FCC's media concentration policies. People were talking about access to channels of publicity, and about editorial power, and things like that.) There are nonetheless some publishers out there who are (1) not trying to create insane copyright policy and (2) personally invested in their books and trying to get interesting and meaningful things out to the public and (3) loving it.

It would really be very interesting to be a part of that in a small way as a published author.