python: Adopt .tool-versions and standardise script/ for Python

python/.tool-versions

@@ -0,0 +1 @@
+python 3.13

python/README.md

@@ -2,16 +2,29 @@
 
 Skeleton project for Python.
 
-## Usage (on MacOS / Linux)
-- `./script/setup` to install dependencies (uses [homebrew](https://brew.sh/))
-- `./script/test` to run the tests
+## Prerequisites
+
+The toolchain this project needs is declared in [`.tool-versions`](./.tool-versions):
+
+```
+python 3.13
+```
+
+Install those however you prefer, as long as they end up on your `PATH`. The quickest route is
+[mise](https://mise.jdx.dev/), which reads the file for you:
 
-## Usage (on Windows)
-- Install Python 3. You can either download from https://www.python.org/downloads/ or run `python` in a terminal to open Windows store Python download.
-- Run `./script/test.bat` in terminal to run tests
+```sh
+mise install
+```
+
+## Usage
+- `./script/setup` to create the virtual environment
+- `./script/test` to run the tests
+- `./script/start` to run the exercise
 
 ## Structure
 - Code located in [`pairing_exercise.py`](./pairing_exercise.py)
 - Tests located in [`test_pairing_exercise.py`](./test_pairing_exercise.py)
 
-However, you're free to organise your code as you like. 
+However, you're free to organise your code as you like.
+

python/script/setup

@@ -1,14 +1,11 @@
 #!/usr/bin/env bash
 
-set -e
+set -euo pipefail
 
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-pushd "$DIR"
+cd "$(dirname "${BASH_SOURCE[0]}")/.."
 
-brew install python3
+python3 -m venv venv
 
-pip3 install virtualenv
-
-virtualenv ../venv
-
-popd
+if [[ -f requirements.txt ]]; then
+  venv/bin/pip install -r requirements.txt
+fi

python/script/start

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+cd "$(dirname "${BASH_SOURCE[0]}")/.."
+
+venv/bin/python pairing_exercise.py

python/script/test

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
-set -e
+set -euo pipefail
 
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+cd "$(dirname "${BASH_SOURCE[0]}")/.."
 
-"$DIR"/../venv/bin/python -m unittest discover
+venv/bin/python -m unittest discover