[Draft] setup.py

This is a draft of a `setup.py`.

I am not sure it it does more harm than good to expose this to the
user or if I should hide a perfectly tailored, `PyPI` distribution
building only one deep in the source tree.

requirements.txt

@@ -0,0 +1,3 @@
+cmake>=3.10.0
+pybind11>=2.2.1
+numpy

setup.py

@@ -0,0 +1,133 @@
+import os
+import re
+import sys
+import platform
+import subprocess
+
+from setuptools import setup, Extension
+from setuptools.command.build_ext import build_ext
+from distutils.version import LooseVersion
+
+
+class CMakeExtension(Extension):
+    def __init__(self, name, sourcedir=''):
+        Extension.__init__(self, name, sources=[])
+        self.sourcedir = os.path.abspath(sourcedir)
+
+
+class CMakeBuild(build_ext):
+    def run(self):
+        try:
+            out = subprocess.check_output(['cmake', '--version'])
+        except OSError:
+            raise RuntimeError(
+                "CMake 3.10.0+ must be installed to build the following " +
+                "extensions: " +
+                ", ".join(e.name for e in self.extensions))
+
+        cmake_version = LooseVersion(re.search(
+            r'version\s*([\d.]+)',
+            out.decode()
+        ).group(1))
+        if cmake_version < '3.10.0':
+            raise RuntimeError("CMake >= 3.10.0 is required")
+
+        for ext in self.extensions:
+            self.build_extension(ext)
+
+    def build_extension(self, ext):
+        extdir = os.path.abspath(os.path.dirname(
+            self.get_ext_fullpath(ext.name)
+        ))
+        cmake_args = [
+            '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=' + extdir,
+            '-DCMAKE_PYTHON_OUTPUT_DIRECTORY=' + extdir,
+            '-DPYTHON_EXECUTABLE=' + sys.executable,
+            # skip building tests & examples
+            '-DBUILD_TESTING:BOOL=OFF',
+            '-DBUILD_EXAMPLES:BOOL=OFF',
+        ]
+
+        cfg = 'Debug' if self.debug else 'Release'
+        build_args = ['--config', cfg]
+
+        if platform.system() == "Windows":
+            cmake_args += [
+                '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}'.format(
+                    cfg.upper(),
+                    extdir
+                )
+            ]
+            if sys.maxsize > 2**32:
+                cmake_args += ['-A', 'x64']
+            build_args += ['--', '/m']
+        else:
+            cmake_args += ['-DCMAKE_BUILD_TYPE=' + cfg]
+            build_args += ['--', '-j2']
+
+        env = os.environ.copy()
+        env['CXXFLAGS'] = '{} -DVERSION_INFO=\\"{}\\"'.format(
+            env.get('CXXFLAGS', ''),
+            self.distribution.get_version()
+        )
+        if not os.path.exists(self.build_temp):
+            os.makedirs(self.build_temp)
+        subprocess.check_call(
+            ['cmake', ext.sourcedir] + cmake_args,
+            cwd=self.build_temp,
+            env=env
+        )
+        subprocess.check_call(
+            ['cmake', '--build', '.'] + build_args,
+            cwd=self.build_temp
+        )
+
+
+# PyPI supports reStructuredText, so try to convert our markdown file
+try:
+    import pypandoc
+    long_description = pypandoc.convert('./README.md', 'rst')
+except (ImportError, RuntimeError):
+    long_description = open('./README.md').read()
+
+# Get the package requirements from the requirements.txt file
+with open('./requirements.txt') as f:
+    install_requires = [line.strip('\n') for line in f.readlines()]
+
+setup(
+    name='openPMD_api',
+    version='0.1.1',
+    author='Fabian Koller, Axel Huebl',
+    author_email='f.koller@hzdr.de, a.huebl@hzdr.de',
+    maintainer='Axel Huebl',
+    maintainer_email='a.huebl@hzdr.de',
+    description='C++ & Python API for Scientific I/O with openPMD',
+    long_description=long_description,
+    url='https://github.com/openPMD/openPMD-api.git',
+    license='LGPL-3.0',
+    ext_modules=[CMakeExtension('openPMD_api')],
+    cmdclass=dict(build_ext=CMakeBuild),
+    zip_safe=False,
+    #tests_require=['pytest'],
+    install_requires=install_requires,
+    #extras_require = {
+    #    'GUI':  ["ipywidgets", "matplotlib", "cython"],
+    #    'plot': ["matplotlib", "cython"],
+    #    'tutorials': ["ipywidgets", "matplotlib", "wget", "cython"]
+    #},
+    #cmdclass={'test': PyTest},
+    #platforms='any',
+    classifiers=[
+        'Development Status :: 3 - Alpha',
+        'Natural Language :: English',
+        'Environment :: Console',
+        'Intended Audience :: Science/Research',
+        'Operating System :: OS Independent',
+        'Topic :: Scientific/Engineering',
+        'Topic :: Database :: Front-Ends',
+        'Programming Language :: C++',
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+    ],
+)