The license of this code is not expressly stated by the original author. I.e., this code is unlicensed (and you likely can't license it unless you work at Yhat or talk to @EricChiang).

Code accompanying blog post which can be found here

churn_measurements.py - Implementations of calibration and discrimination measurements

churn_model.py - A deployable, batch mode compatoble Yhat model for predicting customer churn.

data/churn.csv - Dataset used in blog. Originally published accompanying Discovering Knowledge in Data (Larose; 2004)