Export Yoast SEO Redirection rules

redirection_export.php

<?php
/**
* Generate redirection plugin (https://wordpress.org/plugins/redirection/) compatible csv files from Yoast SEO Premium's redirection.
* 
* Usage: download and put this file to root directory of your WordPress installation. 
* then visit the url, you will see the csv file :) 
* after then WP Adming > Tools > Redirection > import (section)
*
* 
* Don't use this file on production
* 
*/
require_once 'wp-load.php';
$fileName = 'yoast_to_redirection.csv';
header( 'Content-Type: application/excel' );
header( 'Content-Disposition: attachment; filename="' . $fileName . '"' );
$fp = fopen( 'php://output', 'w' );


$rules = get_option( 'wpseo-premium-redirects-base' );

// header info
fputcsv( $fp, array( "source URL", "target URL", "regex", "http code" ) );

foreach ( $rules as $redirect_item ) {
	fputcsv( $fp, array(
		'/' . $redirect_item['origin'],
		'/' . $redirect_item['url'],
		0,
		$redirect_item['type'], // http code
	) );
}


fclose( $fp );

Thank you, such a useful tool since the export is hidden if you downgrade a site!