[probably]

I was introduced to and learned functional programming through Python, beginning with these series of docs:

http://www.ibm.com/developerworks/library/l-prog.html

http://docs.python.org/dev/howto/functional.html

I would say I program primarily, though not strictly, in a functional style in Python, Lisp, and R. For my applications it's more for the purpose of a modularity rather than concurrency-critical issues, so Python's functional programming limitations aren't noticeable (don't know in your case). There is a 'functional' module available for Python which extends on map, filter, and reduce, and lambda's single-epxression limitation does not necessarily make it functional-hostile.