We need to compute the probabilities of defects by shift and defects by type. To compute the expected probabilities, we need to start with some simple sums. The first is the overall sum of all defects, which can be calculated by executing the following command:
total = sum(defects.values())
This is done directly from the values in the Counter object assigned to the defects variable. This will show that there are 309 total defects in the sample set.
We need to get defects by shift as well as defects by type. This means that we'll extract two kinds of subsets from the raw defect data. The by-shift extract will use just one part of the (shift,defect type) key in the Counter object. The by-type will use the ...
