wp cli process something in batches

cli-process-in-batches.php

/**
 * Start point for CLI command to process some posts in batches
 *
 * ## EXAMPLES
 *
 * wp mycommand
 *
 * @subcommand process-posts
 *
 * @param array $args       Positional arguments for the command.
 * @param array $assoc_args Associative arguments for the command.
 * @return void
 */
public function process_posts( $args, $assoc_args ) {
	$batch_size = 250;
	$sleep_time = 1; // seconds
	$sleep_break_count = 100;
	$offset = 0;
	$items_processed = 0;

	$dry_run = ! empty( $assoc_args['dry-run'] );

	do {
		$args = [
			//some other args for WP_Query...
			'cache_results'  => false,
			'offset'         => $offset,
			'no_found_rows'  => true,
			'posts_per_page' => $batch_size
		];

		$query = new \WP_Query( $args );

		if ( $query->post_count > 0 ) {
			foreach ( $query->posts as $post_id ) {
					
				$items_processed++;
				// some logic.....

				if ( ! $dry_run ) {

					// some logic to update DB data if not dry run
					\WP_CLI::line( '[ID: ' . $post_id . '] some message' );
				}
			}

			$offset += $batch_size;

			if ( $items_processed % $sleep_break_count == 0 ) {
				sleep( $sleep_time );
			}
		} else {
			break;
		}
	} while ( $query->post_count > 0 ) {
		\WP_CLI::success( 'Done! ' . $items_processed . ' posts updated.' );
	}
}