setup.py

#!/usr/bin/env python
#
# Copyright 2017, Alexander Shorin
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import os
import subprocess

from setuptools import setup
from setuptools.command.egg_info import egg_info as egg_info_orig
from setuptools.command.sdist import sdist as sdist_orig


ROOT = os.path.dirname(__file__)
GIT = os.path.join(ROOT, '.git')
VERSION = os.path.join(ROOT, 'VERSION')


def main():
    return setup(
        cmdclass={
            'egg_info': egg_info,
            'sdist': sdist,
        },
        version=project_version(),
    )


def project_version():
    version = None

    if not version and os.path.exists(GIT):
        try:
            output = subprocess.check_output(
                ['git', 'describe', '--tags', '--always'],
                stderr=open(os.devnull, 'wb'),
            ).strip().decode()
        except subprocess.CalledProcessError:
            # Can't read the tag. That's probably project at initial stage,
            # or git is not available at all or something else.
            pass
        else:
            try:
                base, distance, commit_hash = output.split('-')
            except ValueError:
                # We're on release tag.
                version = output
            else:
                # Reformat git describe for PEP-440
                version = '{}.{}+{}'.format(base, distance, commit_hash)

    if not version and os.path.exists(VERSION):
        with open(VERSION) as verfile:
            version = verfile.read().strip()

    if not version:
        raise RuntimeError('cannot detect project version')

    return version


class egg_info(egg_info_orig):
    # https://github.com/PyCQA/pylint/issues/73
    def _ensure_stringlike(self, option, what, default=None):
        val = getattr(self, option)
        if val is None:
            setattr(self, option, default)
            return default
        elif isinstance(val, (type(''), type(u''))):
            return val
        return egg_info_orig._ensure_stringlike(self, option, what, default)


class sdist(sdist_orig):
    def run(self):
        # In case when user didn't eventually run `make version` ensure that
        # VERSION file will be included in source distribution.
        version = project_version()
        with open(VERSION, 'w') as verfile:
            verfile.write(version)
        sdist_orig.run(self)


if __name__ == '__main__':
    main()