edit: Works on py3 so nevermind (although, I'm not sure if it's "py3-first", if you would). The book looks nice, and covers a lot of fun topics. My only wish was that he'd used something other than Heroku.
Heroku is just Linux. What do you want , windows server hosting? Using Heroku has been quite educational for me,as for how to manage a production server and good deployement techniques. Care to explain what the problem is?
In short, it simply makes your application respond faster (and scale better) while you still can keep track of all the work done.
I am quite familiar with gearman and beanstalkd, but Celery (as far as I understand it) is a python layer over these implementations. It allows you to write code agnostic of the broker, which helps for portability etc.
Think of things like monitoring, reporting, emailing, analytics, cleaning, archiving... the list goes on.
For all those things you need a job system. Celery is (to my knowledge) the most popular one.
I also just bought the book.
[1] http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-...
You follow along with https://github.com/miguelgrinberg/flasky and basically make a twitter clone -- which is fun. And its nice to be able to checkout the code using git and play with it instead of typing out the contents of the book.
As you can tell from his tutorials, he is a clear writer. And you get a nice taste of cryptography, Bootstrap, and Heroku.
I built http://superquest3.herokuapp.com/ over spring break after completing the book -- and I had never made anything but static websites before.
https://www.kickstarter.com/projects/1223051718/practical-fl... is another flask book project you could check out ...
https://play.google.com/store/books/details/Miguel_Grinberg_...
