I' ve been around long enough that I'm able to learn a lot about a language by looking at source code examples, and by reading the language reference manual. pyblosxom was my first python project, and I definitely learned python on the job, as it were. As I"ve been gearing up to work on the Chandler query system, I felt that maybe it would be a good idea to look at a book or two in order to quickly absorb the pythonic way of thinking. Learning Python was a relatively quick read for me, but nonetheless I learned a number of valuable things. Examples include the use of .pth files, cost models for various looping constructs, the full story on python scope rules, the full story on modules, and class operator overloading (which we use some on pyblosxom -- but it was just nice to have the presentation).

The bottom line: it probably would have saved me some time had I read this book before I started on python (of course the book didn't cover 2.3 back then, though). And for a book on a language, that's a good review in my book.