Use pre-commit CI to automatically fix code style issues

.github/workflows/static_analysis.yml

@@ -0,0 +1,35 @@
+name: Static Analysis
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  job:
+    runs-on: ubuntu-latest
+
+    steps:
+
+    # https://github.com/actions/setup-python
+    - name: Install Python 3.11
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.11'
+
+    - name: Install Python dependencies
+      run: |
+        pip install --upgrade pip
+        pip install black 'black[jupyter]' flake8 isort
+        pip install pre-commit
+
+    # https://github.com/actions/checkout
+    - name: Checkout quantifying
+      uses: actions/checkout@v4
+      with:
+        path: quantifying
+
+    - name: pre-commit
+      run: pre-commit run --show-diff-on-failure --color=always --all-files
+      working-directory: ./quantifying

.pre-commit-config.yaml

@@ -0,0 +1,57 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+default_language_version:
+  python: python3.11
+
+ci:
+    autofix_commit_msg: |
+        [pre-commit.ci] auto fixes from pre-commit.com hooks
+
+        for more information, see https://pre-commit.ci
+    autofix_prs: true
+    autoupdate_branch: ''
+    autoupdate_commit_msg: '[pre-commit.ci] pre-commit autoupdate'
+    autoupdate_schedule: weekly
+    skip: []
+    submodules: false
+
+repos:
+
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.1.0
+    hooks:
+      - id: check-added-large-files
+      - id: check-ast
+      - id: check-case-conflict
+      - id: check-docstring-first
+      - id: check-executables-have-shebangs
+      - id: check-json
+      - id: check-merge-conflict
+      - id: check-toml
+      - id: check-yaml
+      - id: destroyed-symlinks
+      #- id: end-of-file-fixer
+      #- id: mixed-line-ending
+      #  args:
+      #  - --fix=no
+      #- id: trailing-whitespace
+
+  - repo: local
+    hooks:
+      - id: black
+        name: "Black"
+        entry: black
+        language: system
+        types: ["file", "python", "text"]
+
+      - id: flake8
+        name: "Flake8"
+        entry: flake8
+        language: system
+        types: ["file", "python", "text"]
+
+      - id: isort
+        name: "isort"
+        entry: isort --filter-files
+        language: system
+        types: ["file", "python", "text"]

README.md

@@ -76,6 +76,26 @@ follow these steps:
 
 ### Static analysis
 
+#### Using [`pre-commit`][pre-commit]
+1. Install pre-commit
+
+      - Using pip:
+        ```shell
+        pip install pre-commit
+        ```
+      - Using homebrew:
+        ```shell
+        brew install pre-commit
+        ```
+
+2. Install the git hook scripts
+   ```shell
+   pre-commit install
+   ```
+
+It will run on every commit automatically.
+
+#### Using [`dev/tools.sh`][tools-sh] helper script
 The [`dev/tools.sh`][tools-sh] helper script runs the static analysis tools
 (`black`, `flake8`, and `isort`):
 ```shell
@@ -89,6 +109,7 @@ directories to check:
 ```
 
 [tools-sh]: /dev/tools.sh
+[pre-commit]: https://pre-commit.com/
 
 
 ### Resources
@@ -100,12 +121,15 @@ directories to check:
 - [isort][isort]: _A Python utility / library to sort imports_
   - (It doesn't import any libraries, it only sorts and formats them.)
 - [ppypa/pipenv][pipenv]: _Python Development Workflow for Humans._
+- [pre-commit][pre-commit]: _A framework for managing and maintaining
+  multi-language pre-commit hooks._
 
 [ccospyguide]: https://opensource.creativecommons.org/contributing-code/python-guidelines/
 [black]: https://github.com/psf/black
 [flake8]: https://gitlab.com/pycqa/flake8
 [isort]: https://pycqa.github.io/isort/
 [pipenv]: https://github.com/pypa/pipenv
+[pre-commit]: https://pre-commit.com/
 
 
 ### GitHub Actions
@@ -115,7 +139,7 @@ GitHub Actions workflow performs static analysis (`black`, `flake8`, and
 `isort`) on committed changes. The workflow is triggered automatically when you
 push changes to the main branch or open a pull request.
 
-[workflow-static-analysis]: .github/workflows/python_static_analysis.yml
+[workflow-static-analysis]: .github/workflows/static_analysis.yml
 
 
 ## Data sources