function courses_shortcode($atts) {

    extract(shortcode_atts( array(
        'limit' => 16,
        'id' => array(592, 862, 418, 491, 1227, 1015, 847, 738, 541, 1186, 664, 695, 785),
    ), $atts ));

     if ( !is_array($id) ) {
        // then simultaneously parse it into an array and trim white space:
        $id = array_map('trim', explode(', ', $id));
    }

    $q_courses = new WP_Query( array(
        'post_type' => array('course'),
        'posts_per_page'  => $limit,
        'post__in' => $id,
        'orderby' => 'post__in',
    ));

    $video_courses = $q_courses->posts;
    $list = "";

    if ($video_courses) {
        foreach($video_courses as $single_course1) {
            $list .= '<article id="post-'.$single_course1->ID.'" class="all course-item col-md-3 col-xs-12">';
            $list .= do_shortcode( '[course_media course_id="'.$single_course1->ID.'"]' );
            $list .= '<h3 class="course-title"><a href="'.get_the_permalink($single_course1->ID).'">'.get_the_title($single_course1->ID).'</a></h3><div class="entry-content">';
            $list .= do_shortcode( '[course_instructors course_id="'.$single_course1->ID.'" show_divider=no style=list-flat]' );
            $list .= do_shortcode( '[ratings id="'.$single_course1->ID.'"]');
            $list .=  do_shortcode( '[course_cost course_id="'.$single_course1->ID.'"]' );
            $list .=  '<span class="buying-date-3-months">Nutzungslaufzeit: 12 Monate</span></div>';
            $list .= '</article>';
        }
    }

    return $list;
    //return $id;
}
add_shortcode('video-kurse', 'courses_shortcode');