Introduction: The zero-cost stack

If you are starting an “Intro to Financial Accounting” course, you’ve probably got:

  • a textbook,

  • a calculator,

  • and a spreadsheet open…

…and you’re hoping you didn’t miss a sign, a row, or a formula.

This workbook introduces The Hybrid Method:

  • Google Sheets or Excel for drafting (visual, flexible, familiar)

  • LedgerLoom for verification (rigid, strict, deterministic)

Think of LedgerLoom like a spell-checker for accounting:

  • It stops you when your work violates the double-entry invariant.

  • It produces standard artifacts (entries + trial balances) you can compare to your sheet.

What you need

You do not need paid software.

  • A spreadsheet (Google Sheets, Excel, LibreOffice)

  • Python 3.10+ (Windows/macOS/Linux)

  • LedgerLoom (installed from PyPI)

Tip

Using Git Bash on Windows

The command examples in this workbook use a POSIX-style shell. On Windows, Git Bash is a great choice (and it matches what we use in class).

Install LedgerLoom

python -m pip install --upgrade pip
python -m pip install ledgerloom

If the ledgerloom command is not found, you can always run:

python -m ledgerloom --help

Create a workbook project

LedgerLoom uses a small project folder with a config file (ledgerloom.yaml) and CSV inputs.

ledgerloom init --profile workbook my_homework
cd my_homework

This creates:

  • ledgerloom.yaml (project config)

  • config/chart_of_accounts.yaml (your chart of accounts)

  • inputs/<period>/transactions.csv (journal lines)

  • inputs/<period>/adjustments.csv (adjusting entries)

  • outputs/<run_id>/ (artifacts per run)

From there, your workflow is simple:

ledgerloom check --project .
ledgerloom build --project . --run-id run-01

Next: go to Workbook Chapter 0 — Setup and a Runnable Startup Project to run a known-good example and learn what the output folders mean.