version.py

"""
automatically maintains the latest git tag + revision info in a python file

"""

import imp
import os
import subprocess


def get_project_version(version_file):
    version_file = os.path.join(os.path.dirname(os.path.realpath(__file__)), version_file)
    try:
        module = imp.load_source("verfile", version_file)
        file_ver = module.__version__
    except:
        file_ver = None

    try:
        proc = subprocess.Popen(["git", "describe", "--always"],
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
        stdout, stderr = proc.communicate()
        if stdout:
            git_ver = stdout.splitlines()[0].strip().decode("utf-8")
            if git_ver and ((git_ver != file_ver) or not file_ver):
                open(version_file, "w").write("__version__ = '%s'\n" % git_ver)
                return git_ver
    except OSError:
        pass

    if not file_ver:
        raise Exception("version not available from git or from file %r"
                        % version_file)

    return file_ver

if __name__ == "__main__":
    import sys
    get_project_version(sys.argv[1])