README.md

Python totals example

Application behavior

Input	Output
python src/totals.py 10 20 12	42
python src/totals.py 50 -20 12	42
python src/totals.py	0

The CLI reads integer amounts and prints their sum. The check driver launches the application and compares output with literal expected totals.

Run the check

1. Install VKit and Python.
2. Copy this directory to a separate location.
3. Initialize and commit a Git repository there.
4. Run these commands from that directory:

vkit doctor --project .
vkit accept --project .
vkit check run --project . --check totals-behavior
vkit features --project .
vkit console --project .

Coverage

Registered check	Cases
totals-behavior	Empty cart, one positive amount, several positive amounts, mixed signs, negative amounts, and cancellation to zero.

Observe a failure

1. In src/totals.py, replace running += amount with running += amount + 1.
2. Run totals-behavior again. Cases with amounts now produce incorrect totals.
3. Restore the original line and rerun the check.

See the main README for installation and agent setup.