setup.py

#! /usr/bin/env python

import os
import sys
import tempfile
import shutil
import builtins
import textwrap
from numpy.distutils.command.build_ext import build_ext as npy_build_ext

import setuptools
from setuptools.command.build_py import build_py
from setuptools.command.sdist import sdist
try:
    from setuptools.errors import CompileError, LinkError
except ImportError:
    # can remove this except case once we require setuptools>=59.0
    from distutils.errors import CompileError, LinkError

from pythran.dist import PythranBuildExt as pythran_build_ext

DISTNAME = 'scikit-image'
DESCRIPTION = 'Image processing in Python'
MAINTAINER = 'Stefan van der Walt'
MAINTAINER_EMAIL = 'stefan@sun.ac.za'
URL = 'https://scikit-image.org'
LICENSE = 'Modified BSD'
DOWNLOAD_URL = 'https://scikit-image.org/docs/stable/install.html'
PROJECT_URLS = {
    "Bug Tracker": 'https://github.com/scikit-image/scikit-image/issues',
    "Documentation": 'https://scikit-image.org/docs/stable/',
    "Source Code": 'https://github.com/scikit-image/scikit-image'
}

with open('README.md', encoding='utf-8') as f:
    LONG_DESCRIPTION = f.read()

if sys.version_info < (3, 8):

    error = f"""Python {'.'.join([str(v) for v in sys.version_info[:3]])} detected.

scikit-image supports only Python 3.8 and above.

For Python 2.7, please install the 0.14.x Long Term Support release using:

 $ pip install 'scikit-image<0.15'
"""

    sys.stderr.write(error + "\n")
    sys.exit(1)

# This is a bit (!) hackish: we are setting a global variable so that the main
# skimage __init__ can detect if it is being loaded by the setup routine, to
# avoid attempting to load components that aren't built yet:
# the numpy distutils extensions that are used by scikit-image to recursively
# build the compiled extensions in sub-packages is based on the Python import
# machinery.
builtins.__SKIMAGE_SETUP__ = True


# Support for openmp

class ConditionalOpenMP(pythran_build_ext[npy_build_ext]):

    def can_compile_link(self, compile_flags, link_flags):

        if "PYODIDE_PACKAGE_ABI" in os.environ:
            # pyodide doesn't support OpenMP
            return False

        cc = self.compiler
        fname = 'test.c'
        cwd = os.getcwd()
        tmpdir = tempfile.mkdtemp()

        code = ("#include <omp.h>"
                "int main(int argc, char** argv) { return(0); }")

        if self.compiler.compiler_type == "msvc":
            # make sure we build a DLL on Windows
            local_link_flags = link_flags + ["/DLL"]
        else:
            local_link_flags = link_flags

        try:
            os.chdir(tmpdir)
            with open(fname, 'w') as fobj:
                fobj.write(code)
            try:
                objects = cc.compile([fname],
                                     extra_postargs=compile_flags)
            except CompileError:
                return False
            try:
                # Link shared lib rather then executable to avoid
                # http://bugs.python.org/issue4431 with MSVC 10+
                cc.link_shared_lib(objects, "testlib",
                                   extra_postargs=local_link_flags)
            except (LinkError, TypeError):
                return False
        finally:
            os.chdir(cwd)
            shutil.rmtree(tmpdir)
        return True

    def build_extensions(self):
        """ Hook into extension building to set compiler flags """

        compile_flags = list()
        link_flags = list()

        # check which compiler is being used
        if self.compiler.compiler_type == "msvc":
            # '-fopenmp' is called '/openmp' in msvc
            compile_flags += ['/openmp']
        else:
            compile_flags += ['-fopenmp']
            link_flags += ['-fopenmp']
        if 'SKIMAGE_LINK_FLAGS' in os.environ:
            link_flags += [os.environ['SKIMAGE_LINK_FLAGS']]

        if self.can_compile_link(compile_flags, link_flags):
            for ext in self.extensions:
                ext.extra_compile_args += compile_flags
                ext.extra_link_args += link_flags

        super().build_extensions()


with open('skimage/__init__.py', encoding='utf-8') as fid:
    for line in fid:
        if line.startswith('__version__'):
            VERSION = line.strip().split()[-1][1:-1]
            break


def parse_requirements_file(filename):
    with open(filename, encoding='utf-8') as fid:
        requires = [line.strip() for line in fid.readlines() if line]

    return requires


INSTALL_REQUIRES = parse_requirements_file('requirements/default.txt')
extras_require = {
    dep: parse_requirements_file('requirements/' + dep + '.txt')
    for dep in ['docs', 'optional', 'test', 'data']
}


def configuration(parent_package='', top_path=None):
    if os.path.exists('MANIFEST'):
        os.remove('MANIFEST')

    from numpy.distutils.misc_util import Configuration
    config = Configuration(None, parent_package, top_path)

    config.set_options(
        ignore_setup_xxx_py=True,
        assume_default_configuration=True,
        delegate_options_to_subpackages=True,
        quiet=True)

    config.add_subpackage('skimage')

    return config


if __name__ == "__main__":
    cmdclass = {'build_py': build_py,
                'sdist': sdist}
    try:
        # test if build dependencies exist.
        # if not, some commands are still viable.
        # note: this must be kept in sync with pyproject.toml
        from numpy.distutils.core import setup
        import cython  # noqa: F401
        extra = {'configuration': configuration}
        cmdclass['build_ext'] = ConditionalOpenMP
    except ImportError:
        if len(sys.argv) >= 2 and ('--help' in sys.argv[1:] or
                                   sys.argv[1] in ('--help-commands',
                                                   '--version',
                                                   'clean',
                                                   'egg_info',
                                                   'install_egg_info',
                                                   'rotate',
                                                   'sdist')):
            # For these actions, compilation is not required.
            #
            # They are required to succeed for example when pip is
            # used to install scikit-image when Numpy/cython are not
            # yet present in the system.
            from setuptools import setup
            extra = {}
        else:
            print(textwrap.dedent("""
                To install scikit-image from source, you will need NumPy
                and Cython.
                Install NumPy, Cython with your python package manager.
                If you are using pip, the commands are:

                  pip install numpy cython pythran

                For more details, see:

                   https://scikit-image.org/docs/stable/install.html
            """))
            sys.exit(1)

    setup(
        name=DISTNAME,
        description=DESCRIPTION,
        long_description=LONG_DESCRIPTION,
        long_description_content_type="text/markdown",
        maintainer=MAINTAINER,
        maintainer_email=MAINTAINER_EMAIL,
        url=URL,
        license=LICENSE,
        download_url=DOWNLOAD_URL,
        project_urls=PROJECT_URLS,
        version=VERSION,
        classifiers=[
            'Development Status :: 4 - Beta',
            'Environment :: Console',
            'Intended Audience :: Developers',
            'Intended Audience :: Science/Research',
            'License :: OSI Approved :: BSD License',
            'Programming Language :: C',
            'Programming Language :: Python',
            'Programming Language :: Python :: 3',
            'Programming Language :: Python :: 3.8',
            'Programming Language :: Python :: 3.9',
            'Programming Language :: Python :: 3.10',
            'Programming Language :: Python :: 3.11',
            'Programming Language :: Python :: 3 :: Only',
            'Topic :: Scientific/Engineering',
            'Operating System :: Microsoft :: Windows',
            'Operating System :: POSIX',
            'Operating System :: Unix',
            'Operating System :: MacOS',
        ],
        install_requires=INSTALL_REQUIRES,
        extras_require=extras_require,
        python_requires='>=3.8',
        packages=setuptools.find_packages(
            exclude=['doc', 'doc.*', 'benchmarks']),
        package_data={
            # distribute Cython source files in the wheel
            "": ["*.pyx", "*.pxd", "*.pxi", "*.pyi", ""],
            # tests dirs have an __init__.py so are automatically included
        },
        include_package_data=False,
        zip_safe=False,  # the package can run out of an .egg file
        entry_points={},
        cmdclass=cmdclass,
        **extra
    )