xlsx

Use this skill any time a spreadsheet file is the primary input or output. This means any task where the user wants to: open, read, edit, or fix an existing .xlsx, .xlsm, .xltx, .csv, or .tsv file (e.g., adding columns, computing formulas, formatting, charting, cleaning messy data); create a new spreadsheet from scratch or from other data sources; or convert between tabular file formats. Trigger especially when the user references a spreadsheet file by name or path — even casually (like \"the xl

XLSX creation, editing, and analysis | Task | Approach | |---|---| | Create or edit with formulas/formatting | openpyxl — see gotchas below | | Bulk data in or out | pandas (readexcel, toexcel) | | Quick look at a sheet | markitdown file.xlsx — SheetName per sheet; reads .xlsm too. No cell coordinates, so don't plan edits from it | | Read a model (formulas and values) | two loadworkbook passes — see gotchas | 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. Script paths below are relative to this skill's directory. Requirements for every output - Professional font (Arial, Times New Roman) throughout, unless the user says otherwise. - Zero formula errors. Never ship while recalc.py reports errorsfound. If you think an error…