I own more than 100 O'Reilly books and dozens of Python books, since I've been a Python user, instructor and evangelist for 13 years now. The first edition of this book was the first book published about Python by O'Reilly, and it was often compared to Programming Perl at the time. The comparison was very bad for this book: it is much longer, yet shallower than the Camel Book; it tries hard to be funny, but Larry Wall's jokes are less frequent but more effective; it is poorly edited, while the Camel Book is a gem and a true classic.
The pace is excruciatingly slow for a seasoned programmer of any language, but in spite of long and repetitive explanations this book is not accessible to beginners because of excessive, needless jargon and attention to irrelevant details when first introducing language features, making the narrative hard to digest.
It is accurate and up to date, and for this reason I give it 2 stars instead of one. But anyone looking for a Python book will be better served looking elsewhere. From O'Reilly, Alex Martelli's Python in a Nutshell is the best there is to really understand how the language works and how it should be used, even if it is outdated. Python Essential Reference by David Beazley is excellent too, and the 4th edition is very up to date. The Dive into Python books (Python 2 and Python 3 versions exist) are also excellent, and free as in speech. The Quick Python Book by Manning is also good. In fact, every other Python book that I know is a better buy than this one, which probably sells mainly due to the O'Reilly brand and because it was the first. BTW, Martelli, on p. 12 of Python in a Nutshell, 2e, refers readers to nine other books by O'Reilly and other publishers, including two others by Mark Lutz. This is one is not among the recommendations. I think I know why.