FYI, this is part of PacktPub's free daily book giveaway -- every day at midnight UTC (e.g. 4PM PDT) -- or a little after -- the book at the free-learning link

FYI, this is part of PacktPub's free daily book giveaway -- every day at midnight UTC (e.g. 4PM PDT) -- or a little after -- the book at the free-learning link changes to a new title, which can be downloaded in a variety of formats or read online. They sometimes have thematic weeks, e.g. Android, Data Science, etc. (Note: you'll need to set up an account at PacktPub.com to be able to download the free book).