This looks like it might eventually become a useful resource, as there is nothing else out there with its particular approach and combination of topics, and it seems fundamentally sound.

However, I wouldn't recommend trying to learn from it in its current form, unless you already know a lot.

Just skimming over it, I found that it was teeming with grammatical errors and typos, with entire sentences garbled to the point where I couldn't tell what the authors had intended to say. I saw syntax errors in the code samples, which means that they weren't all verified to run as printed. Again, not a real problem except for beginners, but beginners are the target audience.

Finally, there is some utility to the concept of prerequisite that the authors seem to avoid.

This book tries to teach the beginner everything that he might need to know, from what "ls" does in the shell to how to use git and set up virtual environments. Maybe it is practical to go from never having seen the command line to deploying working, secure Django projects just by using a (cleaned up version of) this book, but doesn't it make more sense to learn things in a more solid progression of stages? It's OK to expect the student to already know some basics, and build on those. You don't find a tutorial on arithmetic in a book about topology.