XLSX

xlsx

Create and modify .xlsx workbooks with the openpyxl Python library. Reading an existing spreadsheet to plain text is best done with the built-in os.fs.read_document tool (no install). Use the scripts below to write: new workbooks, cell values, formulas, and basic formatting.

The pattern is python3 -c "<inline script>" (or python3 script.py for longer logic). Keep scripts short and idempotent; always write to a fresh output path.

Setup health check (run first, every session)

Verify with one solo step:

[{ "tool": "os.shell.run", "args": { "cmd": "python3", "args": ["-c", "import openpyxl; print(openpyxl.__version__)"] } }]

Outcome map:

• exit 0 + version → ready, proceed.
• ModuleNotFoundError: openpyxl → enter Setup playbook → "openpyxl missing".
• command not found: python3 → reply that Python 3 is required and stop.

Setup playbook (when prerequisites are missing)

openpyxl missing

Reply (solo reply step):

"The openpyxl library is not installed. I can install it: python3 -m pip install --user openpyxl. Install it?"

On yes:

[{ "tool": "os.shell.run", "args": { "cmd": "python3", "args": ["-m", "pip", "install", "--user", "openpyxl"] } }]

If pip is externally managed (PEP 668), use pipx run --spec openpyxl python or a venv; ask the user which they prefer.

When to use

• "Create an Excel file with these rows", "build a budget spreadsheet".
• "Add a column / formula", "update cell B2", "add a second sheet".
• Generating reports/exports as .xlsx.

When NOT to use

• Reading an .xlsx to summarise — use os.fs.read_document.
• CSV-only work — prefer plain os.fs.write with comma-separated text.
• Charts / pivot tables / macros — out of scope on v1.

Common operations

Create a workbook with a header row and two data rows:

[{ "tool": "os.shell.run", "args": { "cmd": "python3", "args": ["-c", "import openpyxl; wb=openpyxl.Workbook(); ws=wb.active; ws.title='Report'; ws.append(['Name','Amount']); ws.append(['Coffee',4.5]); ws.append(['Tea',3]); ws['B4']='=SUM(B2:B3)'; wb.save('report.xlsx'); print('wrote report.xlsx')"] } }]

Append rows to an existing workbook:

[{ "tool": "os.shell.run", "args": { "cmd": "python3", "args": ["-c", "import openpyxl; wb=openpyxl.load_workbook('report.xlsx'); ws=wb.active; ws.append(['Juice',5]); wb.save('report.xlsx'); print('appended')"] } }]

For anything longer than a couple of statements, write a .py file with os.fs.write first, then run it with python3 script.py.

Rules

1. Always wb.save(<new path>) and report the path; never silently overwrite.
2. Formulas go in as strings starting with = (e.g. '=SUM(A1:A9)').
3. Quote numbers as numbers, not strings, so Excel treats them numerically.
4. For reads, defer to os.fs.read_document — do not reinvent parsing.