Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
The book is easy enough to follow however there are plenty of typos and a gives a feel of haphazard construction, there are hyperlinks in the physical copy of the book for a start... and I believe there is at least as good or better material available online for free. I purchased this book because it had 4 star reviews and because I wanted a physical book, however, they were probably fabricated reviews as this is not a 4 star publication. I had given it 3 stars considering the structure is reasonable and the material close enough and will get you moving but I have had a formal education in IT and Software Development, new people may find it harder to follow and as such may slow your growth compared to other material, for this reason and because I believe the reviews are fabricated I have reduced the review to 2 stars. This is not the bible, check out the offical documentation for the true word of the Python gods, its free anyway.