Case 1 · 2 levels
Holiday season review
Review the 2025 holiday season like a working analyst: monthly revenue, category growth versus last year and the November-to-December change by channel, in SQL and in pandas.
StartThis case unlocks when both chapters are done. The levels are readable now.
Every January, someone asks how the holidays went. The answer is never one number. Sales wants to know whether November and December beat the autumn months, Merchandising wants to know which categories grew against last year, and Marketing wants to know which channel carried December.
This case is that review for Harbor & Pine’s 2025 season. You solve it once in SQL and once in pandas, on the same data, with the same definitions, and the numbers must match. Seeing the same analysis written both ways is the fastest way to become fluent in the second language: the thinking is identical, only the syntax moves.
Levels
- Holiday season review in SQL
from Megan Collins, Head of Sales
date filter, conditional aggregation, count distinct, yoy, mom
- Holiday season review in pandas
from Megan Collins, Head of Sales
merge, groupby, named aggregation, nunique, pivot table, yoy, mom