How to use the patchman.hosts.models.Host.objects.get function in patchman

def import_installed_packages(conn):

    cursor = conn.cursor(MySQLdb.cursors.DictCursor)

    cursor.execute('SELECT * FROM installed_pkgs')
    rows = cursor.fetchall()

    plength = len(rows)
    pbar = progress_bar('Installed Packages', plength)
    i = 0

    for row in rows:
        pbar.update(i+1)
        i += 1
        try:
            host = Host.objects.get(id=row['host_id'])
        except Host.DoesNotExist:
            continue
        arch, c = PackageArchitecture.objects.get_or_create(name=row['arch'])
        package, c = Package.objects.get_or_create(name=PackageName.objects.get(id=row['pkg_id']), version=row['version'], release=row['rel'], arch=arch)
        host.packages.add(package)

    cursor.close()

def clean_tags():
    """ Delete unused tags
    """

    tagged_items = list(TaggedItem.objects.all())
    to_delete = []

    for t in tagged_items:
        hostid = t.object_id
        try:
            # tags are only used for hosts for now
            Host.objects.get(pk=hostid)
        except ObjectDoesNotExist:
            to_delete.append(t)

    tlen = len(to_delete)

    if tlen != 0:
        create_pbar('Removing {0!s} unused tagged items'.format(tlen), tlen)
        for i, t in enumerate(to_delete):
            t.delete()
            update_pbar(i + 1)

def get_host(host=None, action='Performing action'):
    """ Helper function to get a single host object
    """

    host_obj = None
    hostdot = host + '.'
    message = '{0!s} for host {1!s}'.format(action, host)

    try:
        host_obj = Host.objects.get(hostname__startswith=hostdot)
    except ObjectDoesNotExist:
        try:
            host_obj = Host.objects.get(hostname__startswith=host)
        except ObjectDoesNotExist:
            message = 'Host {0!s} does not exist'.format(host)
    except MultipleObjectsReturned:
        matches = Host.objects.filter(hostname__startswith=host).count()
        message = '{0!s} hosts match hostname "{1!s}"'.format(matches, host)

    if verbose:
        print message

    return host_obj