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Xlsx

Create, read, edit Excel .xlsx workbooks and CSVs.

Skill metadata​

SourceBundled (installed by default)
Pathskills/productivity/xlsx
Version1.0.0
AuthorNoora
LicenseMIT
Platformslinux, macos, windows
Tagsexcel, spreadsheet, xlsx, csv, openpyxl, productivity
Related skillsdocx, pdf, powerpoint

Reference: full SKILL.md​

info

The following is the complete skill definition that Noora loads when this skill is triggered. This is what the agent sees as instructions when the skill is active.

Xlsx Skill

Work with Excel .xlsx workbooks using Python and openpyxl: build styled multi-sheet workbooks with formulas and charts, inspect or dump existing files, edit cells and structure, and convert to/from CSV. All helper scripts are argparse CLIs that print JSON and use explicit UTF-8 I/O.

When to Use​

  • Creating .xlsx reports: multiple sheets, number formats, styling, merged cells, freeze panes, autofilter, conditional formatting, charts, data-validation dropdowns.
  • Reading a workbook: sheet inventory, dumping data as JSON or CSV, listing formulas vs cached values.
  • Editing existing files: set cells, append rows, insert/delete rows/columns, copy/rename sheets.
  • CSV interop with type inference and non-UTF-8 encodings.
  • Not for the legacy .xls binary format (use LibreOffice to convert first: soffice --headless --convert-to xlsx old.xls).

Prerequisites​

  • Python 3.10+ with openpyxl (pip install openpyxl). No other third-party packages are needed; everything else is stdlib.
  • Optional: LibreOffice (soffice) for headless recalculation or format conversion.

How to Run​

Run the helper scripts with the terminal tool from this skill's scripts/ directory (every script supports --help):

python scripts/xlsx_create.py spec.json report.xlsx   # build from JSON spec
python scripts/xlsx_read.py report.xlsx --sheets      # inventory
python scripts/xlsx_read.py report.xlsx --json --sheet Data
python scripts/xlsx_read.py report.xlsx --formulas
python scripts/xlsx_edit.py report.xlsx --sheet Data --set B2=42 --recalc
python scripts/csv_to_xlsx.py data.csv out.xlsx --encoding utf-8
python scripts/xlsx_to_csv.py report.xlsx out.csv --sheet Data

Author the JSON spec with write_file, inspect script JSON output with read_file or directly from stdout.

Quick Reference​

TaskCommand
Create workbook from specxlsx_create.py spec.json out.xlsx
Sheet names + dimensionsxlsx_read.py f.xlsx --sheets
Dump sheet as JSONxlsx_read.py f.xlsx --json --sheet S
Dump sheet as CSVxlsx_read.py f.xlsx --csv --out d.csv
List formulas + cached valuesxlsx_read.py f.xlsx --formulas
Set a cell / formulaxlsx_edit.py f.xlsx --set "A1==SUM(B:B)"
Append a rowxlsx_edit.py f.xlsx --append '[1,"x",true]'
Insert 2 rows before row 3xlsx_edit.py f.xlsx --insert-rows 3:2
Copy / rename sheet--copy-sheet Src:New --rename-sheet Old:New
Force recalc on openxlsx_edit.py f.xlsx --recalc
CSV -> styled xlsxcsv_to_xlsx.py in.csv out.xlsx
xlsx -> CSVxlsx_to_csv.py f.xlsx out.csv --encoding utf-8

Procedure​

  1. Create: write a JSON spec (schema documented in xlsx_create.py --help and its docstring). Each sheet supports rows (scalars or styled cell objects), sparse cells overrides, column_widths, row_heights, merges, freeze_panes, autofilter, conditional_formats (cell_is rules and color scales), charts (bar/line/pie from cell ranges), and validations (list dropdowns). Typed values: JSON numbers/bools pass through; dates use {"value": "2026-01-31", "type": "date"}. Number formats are Excel format strings: currency "$#,##0.00", percent "0.0%", date "yyyy-mm-dd".
  2. Formulas: set with "formula": "SUM(B2:B9)" in the spec or --set "C1==SUM(A:A)" in the editor. When writing formulas, add "full_calc_on_load": true (spec) or --recalc (editor); this sets the workbook's fullCalcOnLoad flag so Excel/LibreOffice recompute everything on open. openpyxl itself NEVER evaluates formulas.
  3. Read: --sheets for inventory (names, dimensions, merged ranges, chart count), --json/--csv for data, --formulas to pair each formula string with its cached result. Cached results exist only if the file was last saved by a real spreadsheet app; files fresh from openpyxl return null there. To materialize results headlessly: soffice --headless --convert-to xlsx file.xlsx then reload with --data-only.
  4. Edit: xlsx_edit.py applies renames/copies first, then structural row/column changes, then --set/--append. It edits in place unless --out is given — copy the file first if you need the original.
  5. CSV interop: csv_to_xlsx.py infers int/float/bool/ISO-date per cell and styles the header row; xlsx_to_csv.py writes ISO dates and blank strings for empty cells. Both default to UTF-8 and accept --encoding (e.g. utf-8-sig for Excel-friendly BOM, cp1252 for legacy Windows exports).

Pitfalls​

  • openpyxl does not calculate. Formula results are available only via load_workbook(path, data_only=True) and only when the file was previously saved by Excel/LibreOffice. Otherwise you get None.
  • Insert/delete does not shift references. insert_rows, delete_cols, etc. move cell values but do NOT update merged-cell ranges, formula references, chart anchors, or conditional-format ranges. After structural edits on sheets with merges or formulas, re-check them with --sheets and --formulas and fix manually.
  • data_only=True then save silently discards all formulas (cached values replace them). Never save a workbook loaded that way unless that is the goal.
  • Loading strips charts/images: openpyxl does not round-trip charts, so editing a charted workbook and saving drops the charts. Re-add charts after editing, or avoid re-saving charted files.
  • CSV locale traps: always pass explicit encodings (the scripts already do) and remember European CSVs often use ; delimiters and decimal commas — use --delimiter ';' and expect strings like "12,5" to stay strings.
  • Dates are datetimes: Excel stores dates as serial numbers; openpyxl returns datetime/date objects. Dumps here emit ISO strings.
  • Sheet names are capped at 31 chars and reject [ ] : * ? / \.

Verification​

  • After creating: xlsx_read.py out.xlsx --sheets and confirm sheet names, dimensions, merged ranges, and chart counts match intent.
  • Dump data with --json and compare against the source values.
  • After edits: re-dump the touched range; if formulas were written, confirm --formulas lists them and that --recalc was applied.
  • For a full visual check, open in LibreOffice: soffice --headless --convert-to pdf out.xlsx and inspect the PDF.