Practice / strings dates nulls
PulsePoint gym wants to know how long each membership lasted.
members
Both dates are stored as yyyy-MM-dd strings.
Your task: return member and days — the number of days between started and ended.
Assign your answer DataFrame to result. Row order doesn't matter.
membersinput DataFrame| column | type |
|---|---|
| member | string |
| started | string |
| ended | string |
| member | started | ended |
|---|---|---|
| Ada | 2026-01-01 | 2026-01-11 |
| Ben | 2026-03-01 | 2026-03-08 |
memberdays· 2 rowsParse both strings with F.to_date(col, "yyyy-MM-dd"), then
F.datediff(end, start) — end date first — gives whole days between them.
This problem builds on Strings, Dates & Nulls (~8 min). Pop it open in a new tab if you want a quick recap.