Archive for November, 2008

Cover Design and (Slight) Name Change

November 25, 2008

I just got back from a 10-day trip to CA, partly for the Adobe Max conference but mostly for the QCon conference. Not much actual work on the book done except worked with my cover designer and got the front cover done. You can see it on the book’s main page.

The artwork is a watercolor that I did a number of years ago, which I’ve always liked and (I think) strongly suggests “patterns.”

Advertisements Finished

November 14, 2008

This program extracts code listings and puts them in appropriate places in the code tree off the root directory of the download. If you edit a code file, the program will also take your edits and incorporate them into the .rst file where they came from. I’ve tried to put numerous checks in to make sure that the program doesn’t accidently stomp on anything.

If you say python help (or anything it doesn’t understand), it tells you its options:

Command line options:


        Refresh external code files into .rst files.


Pull the code listings from the .rst files and write each listing into its own file. Will not overwrite if code files and .rst files disagree unless you say “extract -force”.


Ensure that external code files exist and check which external files have changed from what’s in the .rst files. Generate files in the _deltas subdirectory showing what has changed.


        Print all the code listings in the .rst files.

I think I’ve done some interesting things with the design of this program so I”m planning to blog about it; it will go into the “Comprehensions” chapter because it uses a lot of them, but it also has a couple of interesting design patterns.

Moved to BitBucket/Mercurial

November 9, 2008

Based on Yarko’s suggestion, experimented with BitBucket and the Mercurial DVCS and immediately ended up moving the project there. Hard to put my finger on why, but everything seems significantly smoother and easier. The BitBucket site also responds much faster. It has wikis for people who prefer to start by just writing code and text for contributions, if figuring out everything else is too big a hurdle at first.

We’ll need to redo the Developer Guide chapter for this new system, but the ease of working with the new system is worth it.

The project home page has the links to the new system.


November 6, 2008
  • I seem to have the very basics of using Bazaar and Launchpad down. I have a shell alias called “push” which pushes up my current version to the trunk, and I have successfully done this several times.
  • I’ve also figured out how to upload the downloadable packages, which you can get by pressing the “downloads” button on the home page for the project.


  • Figure out how to merge someone else’s edits with the main trunk. Yarko is working on putting up some relatively simple edits, and once he does I’ll experiment with those to figure out how to do it.
  • I have the program mostly designed and working, and I think it will go into the “Comprehensions” chapter because it’s a good example of using those, as well as some design patterns. I still need to test and finalize the “update” command, which actually takes code and puts it back into the document (and is thus a bit riskier so I want to be sure it’s working). One thing I’m doing is trying to use difflib to check to see whether a file has actually changed before updating it into the document, although I’ve always found difflib to be rather arcane and this has slowed me down.

Pushed to Launchpad

November 5, 2008

So I’ve figured out how to use Bazaar enough to push the first version of the book onto the Launchpad site. You can get the current version here. Note that it is quite crude; there’s lots of code examples in the book that don’t work (haven’t been properly translated from their Java versions, usually).

However, you should be able to say “make html” or “build html” (although you’ll need make on your system, which if you’re on windows means the simplest solution is to install cygwin (you need to tell it to add ‘make’, and ‘chere’ is also very useful).

Give it a try, just to see if there are other issues I haven’t figured out.