[citac]

Originally Posted by Starson17

....I have bad news.

Here is what you wanted .. or more accurately, what I thought would work:

((?P<author>[^_]+) - )?(?P<series>.+) - (?P<series_index>\d+) - (?P<title>.*)

Note I moved your close parenthesis and put it around the space-hyphen-space and the author.

Unfortunately, when I did that, it worked great for the titles that have an author, but Calibre threw an error when it did not have an author.

I then tried this ({0,1} says the preceding is there zero or one times):

((?P<author>[^_]+) - ){0,1}(?P<series>.+) - (?P<series_index>\d+) - (?P<title>.*)

but that threw the same error.

ERROR: ERROR: Unhandled exception: <b>AttributeError</b>:'NoneType' object has no attribute 'replace'

Traceback (most recent call last):
  File "site-packages\calibre\gui2\widgets.py", line 74, in do_test
  File "site-packages\calibre\ebooks\metadata\meta.py", line 147, in metadata_from_filename
  File "site-packages\calibre\ebooks\metadata\__init__.py", line 20, in string_to_authors
AttributeError: 'NoneType' object has no attribute 'replace'

I'd need to look at the code to find out why. You may want to post a bug report. I think those should have worked. Calibre will normally substitute "Unknown" for an author name if it's blank, but making the author optional in this way potentially bypasses that code in a way that throws this error.

Sorry, but I'm out of ideas. I've never actually needed an optional author regex, and I'm a bit short on time to test it further.

First of all, thank you very much for your patience in walking me through totally unfamiliar territory for me. I gave up on Calibre the first time due to several reasons, but this time I wanted to try and learn how to use it and customize it as possible to fit my needs.

I will look into posting a bug report for this. In the mean time, I went through the Calibre forum one more time with a fine tooth comb, and found a thread where the OP requested help with something similar. There were several regexes there, and I tried each. Finally, it turned out this worked:

^((?P<author>([^\-_0-9]+)(?=\s*-\s*)(?!\s*-\s*[0-9.]+)|\b))(\s*-\s*)?(\[?(?P<series>[^0-9\-]+) (- )?(?P<series_index>[0-9.]+)\]?\s*-\s*)?(?P<title>.+)

It doesn't add "Unknown" but leaves the author's name completely blank. Why, I have no idea, and I guess you would understand it better than I do. Thanks again.