It's hard to explain this book, mostly because it's hard to get to whom it is targeted.
Is it targeted to people that already know Machine Learning and want to learn Python? No, the book goes into lengths into some algorithms and has "easy to write, but not quite right" code to do so.
Is it targeted to people that know Python but want to learn Machine Learning? No; even if some algorithms are explained in length, some aren't and there is very little "you use this when you have data like that" explanations. Actually, there is very little explanation on where an algorithm should be used.
Is it targeted to people that don't know Python and don't know Machine Learning and want to learn but? This is the gray area of the book: Again, the code is pretty simple and does not follow Python coding standards and the ML part is really shallow on the "when" and "why" sections.
In the end, the book is simply an extended version of Scikit-Learn manual -- and I even have doubts if the manual isn't better because it explains when an algorithm should be used.