All of my ebooks have a filename of the form
author1, author2, ... - [series seriesindex - ] title.*
and I have set up Calibre to read metadata from the filename.
Calibre, however, does not seem to split on ", ". How do I modify the regular expression under "Preferences"->"Tweaks" -> "Splitting multiple author names" (authors_split_regex) to add ", " as a possible separator?
I wouldn't recommend this, to be honest. The general naming convention that Calibre expects as default uses comma to delimit author's first and last name, i.e. either Jane Doe or Doe, Jane. If you fiddle with the splitting regex and then try to import a book with this name pattern, you'll get into trouble - and I don't know if this tweak influences just newly imported books or all books within your library.
But if you want to experiment, this regular expression should work: (?i),?\\s*(and|with|,)\\s+. I would try this on a test library first, though, if I were you.
In general, I highly recommend using an online regex tester (with Python regex flavor) such as this one for working with Calibre, it saved me a lot of headaches in the past.
