Average Refactor Demo

This tiny project lets you practice refactoring using two near-duplicate functions:

• average_age(ages: list[float]) -> float
• average_score(scores: list[float]) -> float

You'll start from the function stubs (raise NotImplementedError), write the simplest implementation (Green), then refactor by extracting shared logic and eventually using a better built-in (sum).

Install & Test (Poetry)

poetry install
poetry run pytest -q

To run only the performance demo (prints timing info):

poetry run pytest -q -k perf

The perf test is for demonstration; it does not assert a strict speed ratio to avoid flakiness across machines.