Given a DataFrame with a ts column of ISO date strings, extract the year, month, and day-of-week (dow, Monday = 0) for each row.
Return a list of dicts {"year", "month", "dow"} in row order.
What the tests check
2 on Run · 3 on Submit01extracts year, month, weekday (Mon=0)
02every component, row by row
Submit runs these and one more check you don’t see, so code written for the visible tests alone can still miss.