Python programming book

Can you recommend a Python programming book for a serious, professional 24-30 hour course for programmers?

I'd like to focus on advanced programming techniques and introduce them to functional programming, rather than teach them what's a while loop (that's assumed to be known) or just teach them syntax, functions and classes (I don't want a "translate Java into Python" course).

Let me know if you find a book that acknowledges that python is an order of magnitude slower than java or C#, and has less feature improvements than any other language on the planet in the past 10 years.

If you want something slow but elegant, try ruby instead.