Reading the title I was expecting some Lisp/Haskell...
While you can do that, Python doesn't make your life easier if you want to go functional, really. There's only map/reduce/filter, one-line lambdas (that get really messy really fast), no currying, etc. (however, comprehensions are fine)
I appreciate the effort of the OP in questioning the fact of dataflow implementations, and I suggest him to further explore the world of functional languages - it's huge and resourceful, while the quality of the content written is surprisingly high on average - as he may even find a working implementation for the problem he was trying to solve (happens way too often to me).
BTW, a quick google brought me to this [1] - I'm not sure if it's exactly what we are talking about, but seems related.