human
Give me a the Python program you requested given the following:
Complete the below
def git_version():

    ''''Return the git revision as a string.
    Copied from numpy setup.py'
    '''
assistant
#Here is the Python program you requested.
    def _minimal_ext_cmd(cmd):
        env = {}
        for k in ['SYSTEMROOT', 'PATH']:
            v = os.environ.get(k)
            if (v is not None):
                env[k] = v
        env['LANGUAGE'] = 'C'
        env['LANG'] = 'C'
        env['LC_ALL'] = 'C'
        out = subprocess.Popen(cmd, stdout=subprocess.PIPE, env=env).communicate()[0]
        return out
    try:
        out = _minimal_ext_cmd(['git', 'rev-parse', 'HEAD'])
        GIT_REVISION = out.strip().decode('ascii')
    except OSError:
        GIT_REVISION = 'Unknown'
    return GIT_REVISION