xlsx

1# XLSX creation, editing, and analysis
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3| Task | Approach |
4|---|---|
5| **Create** or **edit** with formulas/formatting | `openpyxl` — see gotchas below |
6| **Bulk data** in or out | `pandas` (`read_excel`, `to_excel`) |
7| **Quick look** at a sheet | `markitdown file.xlsx` — `## SheetName` per sheet; reads `.xlsm` too. No cell coordinates, so don't plan edits from it |
8| **Read** a model (formulas *and* values) | two `load_workbook` passes — see gotchas |
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10> `openpyxl`, `pandas`, and `markitdown` are preinstalled — do not run `pip install` first; write the script and import directly. Only if an import fails (or the `markitdown` command is missing): `pip install` the missing package.
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12> Script paths below are relative to this skill's directory.
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14## Requirements for every output
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16- **Professional font** (Arial, Times New Roman) throughout, unless the user says otherwise.
17- **Zero formula errors.** Never ship while `recalc.py` reports `errors_found`. If you think an error predates you, prove it: load the *original* with `data_only=True` and look at that cell. An error you introduced looks exactly like one you inherited.
18- **Use formulas, never hardcoded results.** Write `sheet['B10'] = '=SUM(B2:B9)'`, not the Python-computed total. The sheet must recalculate when its inputs change.
19- **Follow the user's spec literally.** Exact tab names, exact column headers, and the formula they spelled out. A redesign that computes something else fails, however elegant.
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