Bulk fixing Author/Title by using regex

[solim]

I imported a collection of books but Author/Title wasn't successfully extracted on many of the books.
Some books have BookAuthor~BookTitle.pdf format and those ended up as
Title: BookAuthor~BookTitle
Author: "Untitled" or some random name

I can use Regex
(?P<author>[^_]+)\~(?P<title>.+)
for Adding new books that would split it properly, but is there a way to apply the regex to all existing books in bulk, either manually selecting all that are wrong, or even better, to apply that if there is ~ in author's name

[enuddleyarbl]

I'm mostly clueless about regex, but as a suggestion, try typing something like

author:"~"

in the library search bar to filter your collection to the subset you want, CTRL-A to select all of them, then go to

Edit Metadata > Edit Metadata in Bulk > Search and Replace

select "Regular Expression" as the Search Mode at the right and try your regex there.

Make some kind of backup before you try anything.