If your only motivation for using Google Go is webscraping, and you want to do you ML in python, I would recommend the following stack:
Python requests for scraping data
MongoDB for caching data (MongoDB's page oriented format makes it a natural home for storing JSON objects commonly returned by APIs)
pymongo for interfacing python and mongodb
scikit-learn for doing your machine learning
This all happens in python and you can extend it multiple processors with multiprocessing or to multiple nodes with django