[Cython] Use setup.cfg to configure the package

This change mirrors the one for the source distribution. This change
results in a non-executable template file
(setup.cfg.in), which makes edits easier.

This change
removes the requirement to template the Python extension into setup.py,
and adds a Setuptools extension module. This results in correct builds
when bdist_wheel is specified and uses package_data properly.

SConstruct

@@ -83,7 +83,9 @@ if "clean" in COMMAND_LINE_TARGETS:
     remove_directory("include/cantera/ext")
     remove_file("interfaces/cython/cantera/_cantera.cpp")
     remove_file("interfaces/cython/cantera/_cantera.h")
-    remove_file("interfaces/cython/setup.py")
+    remove_file("interfaces/cython/setup.cfg")
+    remove_file("interfaces/cython/LICENSE.txt")
+    remove_file("interfaces/cython/README.rst")
     remove_file("interfaces/python_minimal/setup.py")
     remove_file("config.log")
     remove_directory("doc/sphinx/matlab/examples")

interfaces/cython/.gitignore

@@ -2,10 +2,8 @@ cantera/*.cpp
 cantera/*.c
 cantera/data
 cantera/test/data
-setup.py
-scripts/ctml_writer.py
-scripts/ctml_writer
-scripts/ck2cti.py
-scripts/ck2cti
 Cantera.egg-info
 dist
+setup.cfg
+LICENSE.txt
+README.rst

interfaces/cython/SConscript

@@ -74,16 +74,19 @@ ext = localenv.LoadableModule('#build/python/cantera/_cantera{}'.format(module_e
                             SHLIBPREFIX='', LIBSUFFIXES=[module_ext])
 localenv['py_extension'] = ext[0].name
 
-localenv.SubstFile('setup.py', 'setup.py.in')
+setup_cfg = localenv.SubstFile("setup.cfg", "setup.cfg.in")
+readme = localenv.Command("README.rst", "#README.rst", Copy("$TARGET", "$SOURCE"))
+license = localenv.Command("LICENSE.txt", "#build/ext/LICENSE.txt",
+                           Copy("$TARGET", "$SOURCE"))
+localenv.Depends(license, localenv["license_target"])
 build_cmd = ('cd interfaces/cython &&'
              ' $python_cmd_esc setup.py build --build-lib=../../build/python')
-mod = build(localenv.Command('#build/python/cantera/__init__.py', 'setup.py',
+mod = build(localenv.Command("#build/python/cantera/__init__.py", "setup.cfg",
                              build_cmd))
 env['python_module'] = mod
 env['python_extension'] = ext
 
-localenv.Depends(mod, ext)
-localenv.Depends(mod, dataFiles + testFiles)
+localenv.Depends(mod, [ext, dataFiles, testFiles, setup_cfg, readme, license])
 localenv.Depends(ext, localenv['cantera_staticlib'])
 
 for f in (multi_glob(localenv, 'cantera', 'py') +

interfaces/cython/setup.cfg.in

@@ -0,0 +1,69 @@
+[metadata]
+name = Cantera
+version = @cantera_version@
+description = Cantera is an open-source suite of tools for problems involving chemical kinetics, thermodynamics, and transport processes.
+long_description = file: README.rst
+long_description_content_type = text/x-rst
+license_files = LICENSE.txt
+url = https://cantera.org
+author = Cantera Developers
+author_email = steering@cantera.org
+keywords = chemistry physics
+license = BSD 3-Clause License
+classifiers =
+    Development Status :: 5 - Production/Stable
+    Intended Audience :: Education
+    Intended Audience :: Science/Research
+    License :: OSI Approved :: BSD License
+    Operating System :: MacOS :: MacOS X
+    Operating System :: Microsoft :: Windows
+    Operating System :: POSIX :: Linux
+    Programming Language :: C
+    Programming Language :: C++
+    Programming Language :: Cython
+    Programming Language :: Fortran
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: Implementation :: CPython
+    Topic :: Scientific/Engineering :: Chemistry
+    Topic :: Scientific/Engineering :: Physics
+project_urls =
+    Documentation = https://cantera.org/documentation
+    Funding = https://numfocus.org/donate-to-cantera
+    Source = https://github.com/Cantera/cantera
+    Tracker = https://github.com/Cantera/cantera/issues
+
+[options]
+zip_safe = False
+include_package_data = True
+install_requires =
+    numpy >= 1.12.0
+    ruamel.yaml >= 0.15.34
+python_requires = ~=@py_min_ver_str@
+packages =
+    cantera
+    cantera.data
+    cantera.test
+    cantera.test.data
+    cantera.examples
+
+[options.package_data]
+cantera.data = *.*, */*.*
+cantera.test.data = *.*, */*.*
+cantera.examples = */*.*
+cantera = *.pxd
+
+[options.extras_require]
+hdf5 = h5py
+pandas = pandas
+
+[options.entry_points]
+console_scripts =
+    ck2cti = cantera.ck2cti:script_entry_point
+    ctml_writer = cantera.ctml_writer:main
+    ck2yaml = cantera.ck2yaml:script_entry_point
+    cti2yaml = cantera.cti2yaml:main
+    ctml2yaml = cantera.ctml2yaml:main

interfaces/cython/setup.py

@@ -0,0 +1,7 @@
+from setuptools import setup, Extension
+
+extension = Extension("cantera._cantera", sources=[])
+
+setup(
+    ext_modules=[extension],
+)