Extract a setuptools version from the git repository's tags.

version.py

# -*- coding: utf-8 -*-

"""Calculates the current version number.

Uses output of “git describe --long --tags --always --dirty='-dev-$(date +%s)'”
interpreted as <version>-<commits>-<sha>-<dirty>

if commits != 0 and not dirty, return version else return full output.

If "git describe" fails (when install via package, copied src, etc), version is
read from RELEASE-VERSION file.

To use this script, simply import it your setup.py file, and use the results
of get_version() as your package version:

    import version
    setup(
        version=version.get_version(),
        .
        .
        .
    )

This will automatically update the RELEASE-VERSION file.  The RELEASE-VERSION
file should *not* be checked into git but it *should* be included in sdist
tarballs (as should version.py file).  To do this, run:

    echo include RELEASE-VERSION version.py >>MANIFEST.in
    echo RELEASE-VERSION >>.gitignore

With that setup, a new release can be labelled by simply invoking:

    git tag -s v1.0
"""

__author__ = ('Douglas Creager <[email protected]>',
              'Michal Nazarewicz <[email protected]>',
              'Maxime Cottret <[email protected]>', )
__license__ = 'This file is placed into the public domain.'
__maintainer__ = 'Maxime Cottret'
__email__ = '[email protected]'

__all__ = ('get_version')


import os
import re
import subprocess
import sys


_RELEASE_VERSION_FILE = os.path.dirname(__file__) + '/RELEASE-VERSION'

_RE_GIT_DESCRIBE = r"v?(?:(?P<version>[\d.]+)(?P<pre>-\w+[\d.]*)?-(?P<commits>\d+)-g)?(?P<sha>[0-9a-f]{7})(?P<dirty>.\d+)?"

def read_git_version():
    try:
        output = subprocess.run('git describe --long --tags --always --dirty=".$(date +%s)"', shell=True, check=True, stdout=subprocess.PIPE).stdout
        ver = output.splitlines()[0].strip().decode()
    except subprocess.CalledProcessError as e:
        return None

    if not ver:
        return None
    m = re.search(_RE_GIT_DESCRIBE, ver)
    if not m:
        sys.stderr.write('version: git description (%s) is invalid, '
                         'ignoring\n' % ver)
        return None

    version = m.group('version') or '0.0.0'
    if m.group('pre'):
        version += m.group('pre')
    if not m.group('version') or (m.group('commits') and int(m.group('commits')) != 0) or m.group('dirty'):
        version = "{}+{}{}{}".format(version,
                                     m.group('sha'),
                                     '.{}'.format(m.group('commits')) if m.group('commits') else '',
                                     m.group('dirty') or '')
    return version

def read_release_version():
    try:
        fd = open(_RELEASE_VERSION_FILE)
        try:
            ver = fd.readline().strip()
        finally:
            fd.close()
        return ver
    except:
        return None


def write_release_version(version):
    fd = open(_RELEASE_VERSION_FILE, 'w')
    fd.write('%s\n' % version)
    fd.close()


def get_version():
    release_version = read_release_version()
    version = read_git_version() or release_version
    if not version:
        raise ValueError('Cannot find the version number')
    if version != release_version:
        write_release_version(version)
    return version


if __name__ == '__main__':
    print(get_version())

This version builds both PEP-440 and semver2 compatible version string