Disclosure: I received a copy of this book for free from
Addison-Wesley as part of the PyATL Book Club.
I have a copy of the first edition of the Python Essential
Reference that I picked up at IPC 8 back in 2000. It’s largely out of
date by now, given that it covered Python 1.5.2. But at the time it was
one of the few books I always kept close at hand for easy reference.
Over time my reference habits evolved away from paper references in
favor of online materials. Today I cleared a little space on my desk
for the fourth edition of PER by David Beazley, updated to cover Python
2.6 and 3.0.
Pound for pound
Just a little space, mind you, because the book is quite compact (717
pages in 6” x 9” x 1”, easily portable in a backpack or briefcase). This
book, diminutive though it may be, has more information of direct use to
Python programmers than many of the War and Peace-sized tomes you’ll
find elsewhere. If David keeps adding material at this rate, I’m going
to need a magnifying glass for the next edition.
The book is organized into three main sections: Language, Library, and
Extending and Embedding. There is a comprehensive index and the chapter
sequence places related information close together. You will not find
yourself flipping back and forth between an early “prose” chapter to a
later “reference” section.
The language section can serve as a reference guide for Python, though
I think the first chapter title “Tutorial” is a little optimistic
based on the brevity. To be fair, the preface states right up front
that the book is not intended to be an introductory text.
This is not a book for learning Python. It is a book for writing
The coverage of the standard library is where PER really shines. I
have a certain amount of interest in documenting the Python
standard library myself, so I was especially keen to review the
material here. I found it up to date, clearly explained, and
detailed. There is not a lot of sample code, but it is not entirely
devoid of examples. In most cases, the prose descriptions are
sufficient and eliminating code samples let David maintain a readable
style without adding filler material.
I thought I had internalized most of this material long ago, but I
learned a few things by re-reading it.
As the title implies, this is not an exhaustive reference guide. It
covers the essential information that will be useful to the most
readers. As a result, some of the modules are covered in less depth than
others. However, I tend to agree with where focus is placed. For
example, much more space is given to working with sqlite3 and databases
in general than some of the more esoteric modules like dis. The ast
module doesn’t appear at all.
Extending and Embedding
The Extending and Embedding section is one area where plenty of
example code is provided. Three techniques for creating extension
modules are covered: hand coding, ctypes, and SWIG (no surprise, since
SWIG is popular and was written by the author). Examples and commentary
are provided for all three approaches.
Going the other direction, embedding an interpreter in another
application, is also explained. All of the functions from the Python
library useful to someone trying to make their application scriptable
are listed and described, with some basic examples showing how to
communicate between the interpreter and your main application.
Due to the reference style, this should not be your first Python book.
It should absolutely be your second.