Twisted is the Python asynchronous networking framework. It has the reputation of having a fearsome learning curve and I was hoping this book would help me overcome it.
Having now pretty much mastered twisted I can say that this book was less help than it should have been.
It lightly covers the many frameworks available in twisted: servers, clients, web, web servers, web rpc, authentication, mail, nntp, ssh, and processes. There is an example for everything.
The book is missing an explanation of the framework of twisted which is essential to using it. For instance the crucial subject of Deferred items was covered in 4 pages whereas it really deserved at least chapter on its own.
If you want to do something which is covered directly in the book then the book will make it easy. If it isn't covered directly then you'll struggle. I regret to say I got more out of reading twisted's source code than I did from this book.