def get_group_list(user=None, include_default=True):
    '''
    Returns a list of all of the system group names of which the user
    is a member.
    '''
    if HAS_GRP is False or HAS_PWD is False:
        # We don't work on platforms that don't have grp and pwd
        # Just return an empty list
        return []
    group_names = None
    ugroups = set()
    if not isinstance(user, six.string_types):
        raise Exception
    if hasattr(os, 'getgrouplist'):
        # Try os.getgrouplist, available in python >= 3.3
        log.trace('Trying os.getgrouplist for \'{0}\''.format(user))
        try:
            group_names = [
                grp.getgrgid(grpid).gr_name for grpid in
                os.getgrouplist(user, pwd.getpwnam(user).pw_gid)
            ]
        except Exception:
            pass
    else:
        # Try pysss.getgrouplist
        log.trace('Trying pysss.getgrouplist for \'{0}\''.format(user))
        try:
            import pysss  # pylint: disable=import-error
            group_names = list(pysss.getgrouplist(user))
        except Exception:
            pass
    if group_names is None:
        # Fall back to generic code
        # Include the user's default group to behave like
        # os.getgrouplist() and pysss.getgrouplist() do
        log.trace('Trying generic group list for \'{0}\''.format(user))
        group_names = [g.gr_name for g in grp.getgrall() if user in g.gr_mem]
        try:
            default_group = grp.getgrgid(pwd.getpwnam(user).pw_gid).gr_name
            if default_group not in group_names:
                group_names.append(default_group)
        except __HOLE__:
            # If for some reason the user does not have a default group
            pass
    ugroups.update(group_names)
    if include_default is False:
        # Historically, saltstack code for getting group lists did not
        # include the default group. Some things may only want
        # supplemental groups, so include_default=False omits the users
        # default group.
        try:
            default_group = grp.getgrgid(pwd.getpwnam(user).pw_gid).gr_name
            ugroups.remove(default_group)
        except KeyError:
            # If for some reason the user does not have a default group
            pass
    log.trace('Group list for user \'{0}\': \'{1}\''.format(user, sorted(ugroups)))
    return sorted(ugroups)
dataset/ETHPy150Open saltstack/salt/salt/utils/__init__.py/get_group_list