Second this, I'm surprised you don't read more about it here. We use it in production to recommend image searchterms based on unstructured text, and it performs better with a few lines of python code than anything our team could write in a lower level language in months. It's REALLY fast once you've built an index.

The reason for that is a pretty epic list of dependencies (have fun explaining why the prod boxes need a fortran compiler), but in terms of efficiency and speed of development it's an obvious choice.