tasks/D2_data_quality/spec.md

D2: Data Quality + Spec Compliance

Goal

Process the input dataset and produce output that satisfies ALL quality rules.

Hard Requirements

1. Read data/input/records.csv and produce data/output/clean.csv.
2. Script: python clean.py
3. Quality rules:
   • Missing values: Any cell with empty string or "N/A" must be replaced with "MISSING".
   • Sort order: Output must be sorted by score descending, then by name ascending (alphabetical).
   • Deduplication: Rows with the same id must be deduplicated, keeping the row with the higher score.
   • Range check: score must be between 0 and 100 inclusive. Rows outside this range must be dropped entirely.
   • Department correction: Rows where department resolves to "MISSING" AND score is less than 50 must have their department value set to "review_needed" rather than left as "MISSING".
4. Output columns: [id, name, score, department] — exact order.
5. No header row modifications (keep original column names).
6. Output must use UTF-8 encoding with Unix line endings.

Deliverables

• Fixed clean.py in workspace.
• Verifier must confirm all quality rules and produce attestation.