We are a medium-sized academic research lab whose main outputs are new statistical methods for analyzing large datasets. We generally develop in R and MATLAB/Octave.
We
I haven't tried directly connecting Octave with Python beyond setting up Octave apps as a server and having a Python client call in, but I've had some luck integrating R with Python courtesy RPy. In some of our applications we build e.g. a wxPython + matplotlib Python frontend, and call the R scripts directly through RPy.