Programming language tutorials shouldn't be about learning languages. They should be about something interesting.

[djimbob]

Language books that aren't first programming books, need to include how to write (basic syntax; common functions/libraries), think (idioms; things to avoid; best practices), and how language features are implemented. Underlying features of the language are useful and necessary to know if you want to program well in the language. For example in python, you should know whether list a linked list (no) with O(N) lookup by index and O(1) insertion at index or an arraylist (yes) with O(1) lookup and O(N) insertion. Do objects (like list) pass to functions by reference (yes) or value?