spreadsheet

name: spreadsheet description: Use when tasks involve creating, editing, analyzing, or formatting spreadsheets (.xlsx, .csv, .tsv) with formula-aware workflows, cached recalculation, and visual review.

Spreadsheet Skill

Workflow

1. Confirm file type and goal: create, edit, analyze, or visualize
2. Use openpyxl for .xlsx, pandas for analysis/CSV/TSV
3. Recalculate formulas and render sheets before delivery when possible
4. Use formulas for derived values (never hardcode results)
5. Save to output/spreadsheet/, temp files to tmp/spreadsheets/

Dependencies

uv pip install openpyxl pandas          # or pip install
brew install libreoffice poppler        # for rendering (macOS)

Formula Rules

• Formulas for derived values, not hardcoded results
• No dynamic array functions (FILTER, XLOOKUP, SORT, SEQUENCE)
• Use absolute/relative references carefully for copy behavior
• Guard against #REF!, #DIV/0!, #VALUE!, #N/A, #NAME?
• Prefix literal text starting with = with single quote

Rendering

soffice --headless --convert-to pdf --outdir $OUTDIR $INPUT_XLSX
pdftoppm -png $OUTDIR/$BASENAME.pdf $OUTDIR/$BASENAME

Review for: layout, formula results, clipping, spilled text.

Formatting — Existing Files

Render first. Preserve existing formatting exactly. Match styles for newly filled cells.

Formatting — New Files

• Appropriate number/date/currency formats
• Headers visually distinct from data
• Set row heights and column widths for readability
• Sparingly use fill colors, borders, merged cells

Color Conventions

Blue: input | Black: formulas | Green: linked | Gray: constants | Orange: review | Red: error | Purple: control | Teal: KPI highlights

Finance-Specific

• Zeros as –, negatives in red parentheses, multiples as 5.2x
• Units in headers (Revenue ($mm))
• Cite sources in cell comments
• Blue text: inputs, black: formulas, green: links, yellow fill: key assumptions

References

• Examples: references/examples/openpyxl/