fortax-xlsx-manipulationlisted

# Excel workbooks with live formulas Create and edit .xlsx files with **openpyxl** (`pip install openpyxl`). Write the Python, run it, then verify the result. The workbook is the working paper: a reviewer must be able to click any figure and see where it comes from. ## Rules for a Fortax workbook 1. **Formulas, not values.** Every total, difference, tax, percentage and check is an Excel formula (`=SUM(D2:D40)`), never a number computed in Python and pasted. Inputs are the only typed numbers. 2. **Assumptions block.** Rates, thresholds, dates and other inputs sit in one labelled block (a sheet `Inputs` or the top rows), each with its source ("s.40A(3), Income-tax Act 1961 — confirm", "kb, captured 2026-08-01"). Formulas refer to those cells (or named ranges), never to a rate typed inside a formula. 3. **Inputs look different:** blue font for typed inputs, black for formulas (the usual convention); say so in a legend. 4. **Check cells.** Each sheet that must tie has a check row that must be 0 or TRUE (debits - credits, total assets - total liabilities, reconciliation difference), with conditional formatting that turns red when it is not. 5. **Source column** on every data row: file, sheet/page, row or voucher number. 6. **Indian formats:** amounts with lakh grouping, dates dd-mm-yyyy, and the period and entity in the sheet title. 7. **Do not destroy the client's file.** Edit a copy (`<name>_working.xlsx`), never overwrite the original; keep their s