Learn how to use Python to reorganize your XML sitemaps and help you isolate indexing problems on your website's ... all posts are grouped into post-sitemapX.xml sitemap files. ... Write XML Sitemaps.

Those sitemaps can then be combined into a single XML sitemap index file, often named sitemap-index.xml. Essentially, it is a sitemap for sitemaps. You can create multiple sitemap index files.