Is it possible without a patch to initialize a python program from within pd, then to receive the result from the python program? If not, what would be the most painless method to accomplish this?

I've used PD's FUDI protocol to talk to python via socket connection - take a look at the purity project for another example of this as well. Here's my implementation:

https://github.com/hecanjog/pippi.pd/blob/4e490b4dfa9d6cbf8587fcb256317a440f3df667/console.py#L371

(I've switched from using PD as an audio engine to a homebrew python system, so this project is dead at the moment but please feel free to grab anything useful!)