Practice / window functions
Waveform wants a per-genre leaderboard: the two most-played tracks in every genre.
track_plays
Your task: return genre, title, and plays for the two most-played tracks in each genre. If two tracks in a genre tie on plays, break the tie by title (A→Z) and keep the earlier one — so every genre returns exactly two rows.
Assign your answer DataFrame to result. Row order doesn't matter.
track_playsinput DataFrame| column | type |
|---|---|
| title | string |
| genre | string |
| plays | long |
| title | genre | plays |
|---|---|---|
| Neon Skyline | synth | 900 |
| Undertow | synth | 750 |
| Riptide | synth | 750 |
| Paper Moons | synth | 500 |
| Marlow's Theme | indie | 610 |
| Slow Static | indie | 420 |
| Gravel Road | indie | 300 |
genretitleplays· 4 rowsWindow.partitionBy("genre").orderBy(F.col("plays").desc(), F.col("title").asc()).
Add F.row_number().over(w), keep rn <= 2, then select("genre", "title", "plays").
The title tiebreaker makes the pick deterministic when two tracks share a play count.
This problem builds on Window Functions (~9 min). Pop it open in a new tab if you want a quick recap.