[Pelican] Remove Prefix in PATH_METADATA Using Named Regex Group

Question

In Pelican static website, we have the following pages under content directory.

1. pages/index%zh-hant.rst
2. pages/about-us%zh-hant.rst
3. pages/talk/thai-forest-tradition%zh-hant.rst
4. pages/talk/thanissaro/how-to-fall%zh-hant.rst

We want to extract 3 metadata: urlpath, slug, and lang from the path of the pages such that

1. urlpath: empty string

   slug: index

   lang: zh-hant
2. urlpath: empty string

   slug: about-us

   lang: zh-hant
3. urlpath: talk/

   slug: thai-forest-tradition

   lang: zh-hant
4. urlpath: talk/thanissaro/

   slug: how-to-fall

   lang: zh-hant

As you can see, the prefix pages/ are removed from urlpath

Solution

In pelicanconf.py

PATH_METADATA = 'pages/(?P<urlpath>[-a-zA-Z0-9/]*/|)(?P<slug>[-a-zA-Z0-9]*)%(?P<lang>[-_a-zA-Z]{2,7})\.rst'
PAGE_URL = '{urlpath}{slug}/'
PAGE_SAVE_AS = '{urlpath}{slug}/index.html'

Tested on: Ubuntu Linux 22.04, Python 3.10.6.

References: