From 2db63257be966c2bed232c22b7228affdd29a344 Mon Sep 17 00:00:00 2001
From: Liam Keegan <liam@keegan.ch>
Date: Wed, 20 May 2026 09:28:15 +0200
Subject: [PATCH] Update slides and example code with PEP639 license info

---
 calculate-liam/pyproject.toml |  5 +++--
 slides/index.md               | 29 +++++++++++++----------------
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/calculate-liam/pyproject.toml b/calculate-liam/pyproject.toml
index 1898f78..cce7323 100644
--- a/calculate-liam/pyproject.toml
+++ b/calculate-liam/pyproject.toml
@@ -4,17 +4,18 @@ build-backend = "hatchling.build"
 
 [project]
 name = "calculate-liam"
-version = "0.0.8"
+version = "0.0.9"
 dependencies = ["click", "numpy"]
 authors = [
   { name="Liam Keegan", email="liam@keegan.ch" },
 ]
+license = "MIT"
+license-files = ["LICENSE.md"]
 description = "An example package from the SSC Python Packaging course"
 readme = "README.md"
 requires-python = ">=3.8"
 classifiers = [
     "Programming Language :: Python :: 3",
-    "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
 
diff --git a/slides/index.md b/slides/index.md
index 887ab96..d419904 100644
--- a/slides/index.md
+++ b/slides/index.md
@@ -606,7 +606,7 @@ pip install -e .
         …
     pyproject.toml         # defines how to install the package
     README.md              # all projects should have a readme
-    LICENSE                # all projects should have a license
+    LICENSE.md             # all projects should have a license
 ```
 
 ---
@@ -748,38 +748,35 @@ authors = [
 ]
 description = "A simple package to flip a coin or roll dice"
 readme = "README.md"
-classifiers = [
-    "Programming Language :: Python :: 3",
-    "License :: OSI Approved :: MIT License",
-    "Operating System :: OS Independent",
-]
+license = "MIT"
+license-files = ["LICENSE.md"]
 ...
 ```
 
 ---
 
-# License in pyproject.toml
+# Licenses in pyproject.toml
 
-We specified our license using a classifier (see [pypi.org/classifiers](https://pypi.org/classifiers/)):
+We specified our license using the [SPDX identifier](https://spdx.org/licenses/) "MIT" and pointed to the license file:
 
 ```toml
-[project]
-classifiers = [..., "License :: OSI Approved :: MIT License", ...]
+license = "MIT"
+license-files = ["LICENSE.md"]
 ```
 
-This is the preferred method if there is a classifier available for your license.
+This is the current recommended way to specify the license (see [PEP 639](https://peps.python.org/pep-0639)).
 
-Alternatively you can instead point to your license file:
+Here are some older (deprecated) alternatives you may see:
 
 ```toml
-[project]
-license = { file = "LICENSE.txt" }
+classifiers = [..., "License :: OSI Approved :: MIT License", ...]
 ```
 
-Or simply provide the license as plain text:
+```toml
+license = { file = "LICENSE.txt" }
+```
 
 ```toml
-[project]
 license = { text = "MIT" }
 ```