How to display post attachment count in admin post list

Just paste the code below into your function.php file. Once you saved the file, a new column will display the post attachment count on your admin post list.

add_filter('manage_posts_columns', 'posts_columns_attachment_count', 5);
add_action('manage_posts_custom_column', 'posts_custom_columns_attachment_count', 5, 2);
function posts_columns_attachment_count($defaults){
    $defaults['wps_post_attachments'] = __('Att');
    return $defaults;
}
function posts_custom_columns_attachment_count($column_name, $id){
        if($column_name === 'wps_post_attachments'){
        $attachments = get_children(array('post_parent'=>$id));
        $count = count($attachments);
        if($count !=0){echo $count;}
    }
}

Thanks to Kevin Chard for the tip!