lesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splitslesson 1 of 5 · labels, features, and train/test splits
Checkpoint
One last thing before we move on. pass this to mark the lesson done, or skip and keep moving. hop to the next when you're ready.
Build the split report. Split the six rows by time at month 2, then print: the sizes of each side, the label's positive rate on each side (:.0%), and whether the rates match. (Matching base rates is what stratify=y buys you in a random split — a time split has to earn it, so you CHECK.)