OK, thanks, but when I make a part optional, when is it used? Is it used when there is more data left after the other parts have been filled?
I try "(?P<author>.+) - (?P<series>.+)? - (?P<title>[^_]+)" but the series part is not bypassed when there are fewer then two dashes in the name. Consequently, the title becomes "Al Sarrantonio - Pumpkin Head", instead of what I want it to be.