Drop 39

.github/workflows/main.yml

@@ -15,7 +15,6 @@ jobs:
     strategy:
       matrix:
         python-version:  # All Python versions supported by Impulse.
-          - "3.9"
           - "3.10"
           - "3.11"
           - "3.12"

CHANGELOG.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+latest
+------
+
+* Drop support for Python 3.9.
+
 2.1 (2025-10-31)
 ----------------
 

docs/conf.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # Configuration file for the Sphinx documentation builder.
 #

justfile

@@ -58,6 +58,10 @@ lint:
     @echo
     @echo '👍 {{GREEN}} Linting all good.{{NORMAL}}'
 
+# Fix any ruff errors
+autofix:
+    @uv run ruff check --fix
+
 # Build docs.
 build-docs:
     @uv run --group=docs sphinx-build -b html docs dist/docs --fail-on-warning --fresh-env --quiet
@@ -72,4 +76,10 @@ check:
     @just lint
     @just build-docs
     @just test-all
-    @echo '👍 {{GREEN}} Linting, docs and smoke tests all good.{{NORMAL}}'
+    @echo '👍 {{GREEN}} Linting, docs and smoke tests all good.{{NORMAL}}'
+
+# Upgrade Python code to the supplied version. (E.g. just upgrade 310)
+upgrade-python MIN_VERSION:
+    @find {docs,src,tests} -name "*.py" -not -path "tests/assets/*" -exec uv run pyupgrade --py{{MIN_VERSION}}-plus --exit-zero-even-if-changed {} +
+    @just autofix
+    @just format

pyproject.toml

@@ -6,7 +6,7 @@ description = "Command line interface for analyzing Python imports."
 authors = [
     {name = "David Seddon", email = "david@seddonym.me"},
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "click>=6",
     "grimp==3.13",
@@ -20,7 +20,6 @@ classifiers = [
     "Operating System :: POSIX",
     "Operating System :: Microsoft :: Windows",
     "Programming Language :: Python",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
@@ -84,6 +83,7 @@ import-linter = { workspace = true }
 dev = [
     "mypy>=1.18.2",
     "pre-commit>=4.3.0",
+    "pyupgrade>=3.21.0",
     "ruff>=0.13.2",
 ]
 docs = [

src/impulse/application/use_cases.py

@@ -1,9 +1,8 @@
 from collections.abc import Set
-from typing import Callable
+from collections.abc import Callable
 import itertools
 import grimp
 from impulse import ports, dotfile
-from typing import Optional
 
 
 def draw_graph(
@@ -64,7 +63,7 @@ def prepare_graph(self, grimp_graph: grimp.ImportGraph, children: Set[str]) -> N
 
     def build_edge(
         self, grimp_graph: grimp.ImportGraph, upstream: str, downstream: str
-    ) -> Optional[dotfile.Edge]:
+    ) -> dotfile.Edge | None:
         raise NotImplementedError
 
 
@@ -77,7 +76,7 @@ def prepare_graph(self, grimp_graph: grimp.ImportGraph, children: Set[str]) -> N
 
     def build_edge(
         self, grimp_graph: grimp.ImportGraph, upstream: str, downstream: str
-    ) -> Optional[dotfile.Edge]:
+    ) -> dotfile.Edge | None:
         if grimp_graph.direct_import_exists(importer=downstream, imported=upstream):
             return dotfile.Edge(source=downstream, destination=upstream)
         return None
@@ -94,7 +93,7 @@ def __init__(
         self.module_name = module_name
         self.show_import_totals = show_import_totals
         self.show_cycle_breakers = show_cycle_breakers
-        self.cycle_breakers: Optional[set[tuple[str, str]]] = None
+        self.cycle_breakers: set[tuple[str, str]] | None = None
 
     def should_concentrate(self) -> bool:
         # We need to see edge direction emphasized separately.
@@ -123,15 +122,15 @@ def _get_coarse_grained_cycle_breakers(
         return coarse_grained_cycle_breakers
 
     @staticmethod
-    def _get_self_or_ancestor(candidate: str, ancestors: Set[str]) -> Optional[str]:
+    def _get_self_or_ancestor(candidate: str, ancestors: Set[str]) -> str | None:
         for ancestor in ancestors:
             if candidate == ancestor or candidate.startswith(f"{ancestor}."):
                 return ancestor
         return None
 
     def build_edge(
         self, grimp_graph: grimp.ImportGraph, upstream: str, downstream: str
-    ) -> Optional[dotfile.Edge]:
+    ) -> dotfile.Edge | None:
         if grimp_graph.direct_import_exists(
             importer=downstream, imported=upstream, as_packages=True
         ):

tests/unit/application/test_use_cases.py

@@ -1,4 +1,3 @@
-from typing import Optional
 from impulse.application import use_cases
 from copy import copy
 from impulse import dotfile
@@ -59,7 +58,7 @@ def build_fake_graph(package_name: str) -> grimp.ImportGraph:
 
 class SpyGraphViewer(ports.GraphViewer):
     def __init__(self) -> None:
-        self.called_with_dot: Optional[dotfile.DotGraph] = None
+        self.called_with_dot: dotfile.DotGraph | None = None
 
     def view(self, dot: dotfile.DotGraph) -> None:
         self.called_with_dot = dot