An xlsx is generated with the preinstalled openpyxl library from a
generator script. Keep the generator under .src/: it is the editable
source for future revisions, and the binary is always regenerated from it.
| Task | Path |
|---|---|
| Create, or edit with formulas and formatting | openpyxl |
| Quick look at an existing sheet | muse.read (converted to markdown, paged); it carries no cell coordinates, so never plan edits from it |
| Read a workbook's model (formulas AND their values) | two load_workbook passes; see /opt/hatch/skills/artifacts/spreadsheet/references/formulas.md |
| Bulk or messy tabular data in or out | Python csv from the standard library; pip install --break-system-packages pandas when a task genuinely needs it |
| Design, structure, number formats, model conventions | /opt/hatch/skills/artifacts/spreadsheet/references/visual.md |
| Formulas, recalculation, editing existing workbooks | /opt/hatch/skills/artifacts/spreadsheet/references/formulas.md |
Requirements on every delivered workbook:
- Set a non-empty
workbook.properties.titleand a human-readable filename. Data enters the workbook from the build's gathered content only; a value you do not have is a blank cell or a question, never an invented number. - Write formulas, never precomputed results:
sheet["B10"] = "=SUM(B2:B9)", not the Python-computed total. The sheet must recalculate when its inputs change. - Follow the user's spec literally: their exact tab names, exact column headers, and the formula they spelled out. A redesign that computes something else fails, however elegant.
- Zero formula errors at delivery: run the recalculation gate below and fix what it names.
- Document assumptions and hardcoded numbers where the reader will see them (a cell comment or an adjacent labeled cell), citing the real source when one exists and saying plainly when the number came from the user.
- A workbook created for someone to fill in gets a short legend naming the cells to edit and one example row of realistic values; never add an example row to a file you were asked to edit.
Scripts
| Script | What it does |
|---|---|
/opt/hatch/skills/artifacts/scripts/recalc_xlsx.py |
Recalculates the workbook in place through headless LibreOffice and reports every formula-error cell as JSON; mandatory whenever the file contains formulas. errors_found exits 0: read the JSON, not the exit code |
/opt/hatch/skills/artifacts/scripts/validate_xlsx.py |
Opens the workbook read-back: zip integrity, sheet parts, populated-cell counts; do not deliver a link while it fails. A csv output gets no reader check |
Verification
Run recalc_xlsx.py (when formulas exist), then validate_xlsx.py, then
follow /opt/hatch/skills/artifacts/testing/SKILL.md. A clean recalculation proves
the formulas evaluate, not that they are right: spot-check two or three
formulas pull the values you expect before building out a grid.