Build: migrate to pyproject.toml

setup.py is now legacy
Migrate to pyproject.toml

To simplify things, move the package to a src folder, which is the standard way to
organize a Python package (this might open the possibility to migrate the tests to pytest too, without sys.path insert hacks)

Drop Python 3.6 support due to:
pypa/setuptools#3269 (comment)
The pyproject.toml file we are shipping is not compatible with Pip 21.X, and Pip 22.X dropped support for Python 3.6

Author: iMichka

.github/workflows/tests.yml

@@ -8,14 +8,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: ubuntu-20.04
-            compiler: gcc
-            version: "9"
-            python-version: "3.6"
-            castxml: "castxml"
-            castxml-epic: 0
-            cppstd: "-std=c++98"
-
           - os: ubuntu-20.04
             compiler: gcc
             version: "9"
@@ -88,8 +80,9 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Display Python version
         run: python -c "import sys; print(sys.version)"
-      - name: Install pycodestyle
-        run: pip install pycodestyle
+      - name: Install Python lib and test libs
+        run: |
+          pip install '.[test]'
       - name: Run pycodestyle
         run: pycodestyle . --exclude=docs
       - name: Setup castxml for Linux
@@ -103,9 +96,6 @@ jobs:
       - name: Setup castxml config
         if: matrix.compiler == 'gcc' && matrix.version == '9'
         run: mv unittests/configs/gcc9.cfg unittests/xml_generator.cfg;
-      - name: Install Python lib and test libs
-        run: |
-          pip install .[test]
       - name: Run tests
         run: |
           export PATH=~/castxml/bin:$PATH

docs/conf.py

@@ -16,11 +16,12 @@
 import os
 import sphinx_rtd_theme
 import subprocess
+import importlib.metadata
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.insert(0, os.path.abspath('.') + "/../")
+sys.path.insert(0, os.path.abspath('.') + "/../src")
 
 from release_utils import utils  # nopep8
 
@@ -58,9 +59,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = utils.find_version("../pygccxml/__init__.py")
+version = importlib.metadata.version("pygccxml")
 # The full version, including alpha/beta/rc tags.
-release = utils.find_version("../pygccxml/__init__.py")
+release = version
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

docs/releasing.rst

@@ -0,0 +1,64 @@
+[build-system]
+requires = ["setuptools", "wheel"]
+
+[project]
+name = "pygccxml"
+description = "Python package for easy C++ declarations navigation."
+authors = [
+    {name = "Michka Popoff", email = "michkapopoff@gmail.com"},
+    {name = "Insight Software Consortium", email = "castxml@public.kitware.com"},
+    {name = "Roman Yakovenko", email = "romanyakovenko@gmail.com"},
+]
+license = {file = "LICENSE.rst"}
+keywords = [
+  "C++",
+  "XML",
+  "declaration parser",
+  "CastXML",
+  "gccxml",
+]
+version = "2.3.0"
+
+classifiers = [
+  "Development Status :: 5 - Production/Stable",
+  "Environment :: Console",
+  "Intended Audience :: Developers",
+  "Operating System :: MacOS :: MacOS X",
+  "Operating System :: Microsoft :: Windows",
+  "Operating System :: POSIX",
+  "Programming Language :: Python :: 3.7",
+  "Programming Language :: Python :: 3.8",
+  "Programming Language :: Python :: 3.9",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: Implementation :: CPython",
+  "Programming Language :: Python :: Implementation :: PyPy",
+  "Topic :: Software Development",
+]
+
+dependencies = [
+  'importlib-metadata >= 4.6; python_version < "3.10"', # Not required for 3.8+, but fixes a stdlib bug
+]
+
+[project.urls]
+Homepage = "https://github.com/CastXML/pygccxml"
+Documentation = "https://readthedocs.org/projects/pygccxml/"
+Repository = "https://github.com/CastXML/pygccxml"
+Changelog = "https://github.com/CastXML/pygccxml/CHANGELOG.md"
+
+[options]
+python_requires = ">=3.7"
+
+[project.optional-dependencies]
+test = [
+  "coverage",
+  "coveralls",
+  "pycodestyle",
+]
+docs = [
+  "sphinx",
+  "sphinx_rtd_theme",
+]
+examples = [
+  "notebook",
+]

pyproject.toml

@@ -26,6 +26,7 @@
 
 """
 
+import sys
 import warnings
 
 from . import declarations
@@ -41,4 +42,16 @@
 # TODO:
 # 1. Add "explicit" property for constructors
 
-__version__ = '2.3.0'
+version = sys.version_info
+
+if version < (3, 8):
+    import importlib_metadata as metadata
+elif version < (3, 9, 10) or (3, 10, 0) <= version < (3, 10, 2):
+    try:
+        import importlib_metadata as metadata
+    except ModuleNotFoundError:
+        from importlib import metadata
+else:
+    from importlib import metadata
+
+__version__ = metadata.version("pygccxml")