Add linting to CI via pre-commit

.flake8

@@ -0,0 +1,2 @@
+[flake8]
+max_line_length = 88

.github/PULL_REQUEST_TEMPLATE.md

@@ -8,4 +8,4 @@ It should describe the change to be made.
 
 Most PRs will require an issue number. Trivial changes, like fixing a typo,
 do not need an issue.
--->
+-->

.github/workflows/lint.yml

@@ -0,0 +1,14 @@
+name: Lint
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: "3.x"
+      - uses: pre-commit/action@v3.0.0

.pre-commit-config.yaml

@@ -0,0 +1,40 @@
+repos:
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v3.2.2
+    hooks:
+      - id: pyupgrade
+        args: [--py37-plus]
+
+  - repo: https://github.com/psf/black
+    rev: 22.10.0
+    hooks:
+      - id: black
+        args: [--target-version=py37]
+
+  - repo: https://github.com/PyCQA/isort
+    rev: 5.10.1
+    hooks:
+      - id: isort
+
+  - repo: https://github.com/PyCQA/flake8
+    rev: 5.0.4
+    hooks:
+      - id: flake8
+        additional_dependencies: [flake8-2020]
+
+  - repo: https://github.com/pre-commit/pygrep-hooks
+    rev: v1.9.0
+    hooks:
+      - id: python-check-blanket-noqa
+
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.3.0
+    hooks:
+      - id: check-json
+      - id: check-merge-conflict
+      - id: check-yaml
+      - id: end-of-file-fixer
+      - id: trailing-whitespace
+
+ci:
+  autoupdate_schedule: quarterly

LICENSE

@@ -113,4 +113,4 @@ Affirmer's express Statement of Purpose.
   CC0 or use of the Work.
 
 For more information, please see
-<https://creativecommons.org/publicdomain/zero/1.0/>
+<https://creativecommons.org/publicdomain/zero/1.0/>

Makefile

@@ -38,6 +38,7 @@ help:
 	@echo "  linkcheck  to check all external links for integrity"
 	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
 	@echo "  check      to run a check for frequent markup errors"
+	@echo "  lint       to lint all the files"
 
 .PHONY: clean
 clean: clean-venv
@@ -186,3 +187,8 @@ check: ensure-venv
 serve:
 	@echo "The 'serve' target was removed, use 'htmlview' instead" \
 	      "(see https://github.com/python/cpython/issues/80510)"
+
+.PHONY: lint
+lint: venv
+	$(VENVDIR)/bin/python3 -m pre_commit --version > /dev/null || $(VENVDIR)/bin/python3 -m pip install pre-commit
+	$(VENVDIR)/bin/python3 -m pre_commit run --all-files

_extensions/custom_roles.py

@@ -32,11 +32,12 @@ def role(name, rawtext, text, lineno, inliner, _options=None, _content=None):
             url_text = text
         url = pattern.format(url_text)
         # don't create a reference if the text starts with !
-        if text.startswith('!'):
+        if text.startswith("!"):
             node = nodes.literal(rawtext, text[1:])
         else:
-            node = nodes.reference(rawtext, '', nodes.literal(rawtext, text),
-                                   refuri=url, internal=False)
+            node = nodes.reference(
+                rawtext, "", nodes.literal(rawtext, text), refuri=url, internal=False
+            )
         return [node], []
 
     return role

conf.py

@@ -6,15 +6,15 @@
 sys.path.insert(0, os.path.abspath(".") + "/_extensions")
 
 extensions = [
-    'custom_roles',
-    'sphinx.ext.intersphinx',
-    'sphinx.ext.todo',
-    'sphinx_copybutton',
-    'sphinxext.rediraffe',
+    "custom_roles",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.todo",
+    "sphinx_copybutton",
+    "sphinxext.rediraffe",
 ]
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # General information about the project.
 project = "Python Developer's Guide"
@@ -23,18 +23,18 @@
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 exclude_patterns = [
-    '_build',
-    'venv*',
-    'env*',
-    'README.rst',
-    '.github',
+    "_build",
+    "venv*",
+    "env*",
+    "README.rst",
+    ".github",
 ]
 
-html_theme = 'furo'
+html_theme = "furo"
 html_theme_options = {}
-html_static_path = ['_static']
+html_static_path = ["_static"]
 html_css_files = [
-    'devguide_overrides.css',
+    "devguide_overrides.css",
 ]
 html_logo = "_static/python-logo.svg"
 
@@ -46,7 +46,7 @@
 # http://www.sphinx-doc.org/en/stable/config.html?highlight=linkcheck#confval-linkcheck_anchors_ignore
 linkcheck_anchors_ignore = [
     # match any anchor that starts with a '/' since this is an invalid HTML anchor
-    r'\/.*',
+    r"\/.*",
 ]
 rediraffe_redirects = {
     "clang.rst": "advanced-tools/clang.rst",
@@ -89,17 +89,17 @@
 
 linkcheck_ignore = [
     # The voters repo is private and appears as a 404
-    'https://github.com/python/voters/',
+    "https://github.com/python/voters/",
     # The python-core team link is private, redirects to login
-    'https://github.com/orgs/python/teams/python-core',
+    "https://github.com/orgs/python/teams/python-core",
     # The Discourse groups are private unless you are logged in
-    'https://discuss.python.org/groups/staff',
-    'https://discuss.python.org/groups/moderators',
-    'https://discuss.python.org/groups/admins',
+    "https://discuss.python.org/groups/staff",
+    "https://discuss.python.org/groups/moderators",
+    "https://discuss.python.org/groups/admins",
 ]
 
 intersphinx_mapping = {
-    'python': ('https://docs.python.org/3', None),
+    "python": ("https://docs.python.org/3", None),
 }
 
 todo_include_todos = True

developer-workflow/lang-changes.rst

@@ -86,4 +86,3 @@ to inform others who may propose a similar language change in the future.
 .. _Ideas Discourse category: https://discuss.python.org/c/ideas/6
 .. _Status Quo Wins a Stalemate: https://www.curiousefficiency.org/posts/2011/02/status-quo-wins-stalemate.html
 .. _Justifying Python Language Changes: https://www.curiousefficiency.org/posts/2011/02/justifying-python-language-changes.html
-