Do you mind elaborating on what 'functional' libraries exist in python? I've practiced a bit using the whole map-reduce paradigm in different ways in python, but I'm not really sure what you mean beyond that.
I once read a quote that when you're using itertools frequently enough in your Python code you're one step away from jumping to a language like Haskell.
I've heard that the OReilly Haskell book was one of the most bought books at PyCon.
My progression went similarly - I started using map, reduce, filter and list comprehension a lot, then moved on to itertools and functools and then decided what I really wanted was a functional by default language. That, the great concurrency support and the desire to learn a lisp-based language properly[1] made me choose Clojure.
It seems that this progression is actually fairly common. I still use Python for quick'n'dirty scripts (especially as a shell scripting alternative) and for web development (for other people; I use Clojure for my own code).
[1] I already knew some Scheme, but never used it for any real projects.
