Laid out infrastructure for switching to black formatting all code.

.github/pull_request_template.md

@@ -14,6 +14,7 @@ Fixes # (issue)
 
 - [ ] I have performed a self-review of my own code
 - [ ] I have run [clang-format](https://docs.openmc.org/en/latest/devguide/styleguide.html#automatic-formatting) (version 15) on any C++ source files (if applicable)
+- [ ] I have run [black](https://black.readthedocs.io/en/stable/index.html) on any Python source files (if applicable)
 - [ ] I have followed the [style guidelines](https://docs.openmc.org/en/latest/devguide/styleguide.html#python) for Python source files (if applicable)
 - [ ] I have made corresponding changes to the documentation (if applicable)
 - [ ] I have added tests that prove my fix is effective or that my feature works (if applicable)

.github/workflows/format-check.yml

@@ -1,4 +1,4 @@
-name: C++ Format Check
+name: Format Check
 
 on:
   # allow workflow to be run manually
@@ -30,3 +30,16 @@ jobs:
       - name: Failure Check
         if: steps.linter.outputs.checks-failed > 0
         run: echo "Some files failed the formatting check! See job summary and file annotations for more info" && exit 1
+
+  python-format-test:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v5
+        with: 
+          python-version: 3.12
+      - run: pip install .[format]
+        name: install black
+      - run: black --check openmc/ tests/
+        name: Check if anything needs to be black formatted

README.md

@@ -6,6 +6,7 @@
 [![dockerhub-publish-develop-dagmc](https://github.com/openmc-dev/openmc/workflows/dockerhub-publish-develop-dagmc/badge.svg)](https://github.com/openmc-dev/openmc/actions?query=workflow%3Adockerhub-publish-develop-dagmc)
 [![dockerhub-publish-develop](https://github.com/openmc-dev/openmc/workflows/dockerhub-publish-develop/badge.svg)](https://github.com/openmc-dev/openmc/actions?query=workflow%3Adockerhub-publish-develop)
 [![conda-pacakge](https://anaconda.org/conda-forge/openmc/badges/version.svg)](https://anaconda.org/conda-forge/openmc)
+[![black-style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 
 The OpenMC project aims to provide a fully-featured Monte Carlo particle
 transport code based on modern methods. It is a constructive solid geometry,

docs/source/devguide/styleguide.rst

@@ -142,11 +142,11 @@ Doxygen commands, e.g., ``\brief`` instead of ``@brief``.
 Python
 ------
 
-Style for Python code should follow PEP8_.
+Style for Python code should follow PEP8_, and be formatted with black_.
 
 Docstrings for functions and methods should follow numpydoc_ style.
 
-Python code should work with Python 3.8+.
+Python code should work with Python 3.11+.
 
 Use of third-party Python packages should be limited to numpy_, scipy_,
 matplotlib_, pandas_, and h5py_. Use of other third-party packages must be
@@ -167,3 +167,4 @@ represent a filesystem path should work with both strings and Path_ objects.
 .. _pathlib: https://docs.python.org/3/library/pathlib.html
 .. _os: https://docs.python.org/3/library/os.html
 .. _Path: https://docs.python.org/3/library/pathlib.html#pathlib.Path
+.. _black: https://black.readthedocs.io/en/stable/index.html

pyproject.toml

@@ -51,6 +51,8 @@ docs = [
 test = ["packaging", "pytest", "pytest-cov", "colorama", "openpyxl"]
 ci = ["cpp-coveralls", "coveralls"]
 vtk = ["vtk"]
+format = ["black~=24.8"]
+develop = ["openmc[test,format]"]
 
 [project.urls]
 Homepage = "https://openmc.org"
@@ -67,6 +69,10 @@ exclude = ['tests*']
 "openmc.data" = ["*.txt", "*.DAT", "*.json", "*.h5"]
 "openmc.lib" = ["libopenmc.dylib", "libopenmc.so"]
 
+[tool.black]
+target-version = ["py311", "py312", "py313"]
+line-length = 88
+
 [project.scripts]
 openmc-ace-to-hdf5 = "scripts.openmc_ace_to_hdf5:main"
 openmc-plot-mesh-tally = "scripts.openmc_plot_mesh_tally:main"