This book is exactly what it claims, a pocket reference - well almost, it lacks an index which reduces its value. If you are already a fluent Python programmer I doubt that you would have much use for it. If you are an occasional user of Python who has made the effort to learn the language but do not use it enough to keep details at your fingertips, this book might help. I must confess that I think the lack of an index seriously devalues it and I suspect that a somewhat larger reference book would meet the needs of rather more people.