Help with RegEx to parse title with colon

[racergirl76]

I've been combing these forums for a week looking for a solution and am now admitting defeat.

I stongly prefer the Title field contain the full (long) title of a book:
"Maintitle of Book: Subtitle aka Strapline"

For more effencient use of the title contents for writing to disc/saving, templates, and for plugboards, I need to parse the title into two userdefined columns
"#maintitle" & "#subtitle"

So, I tried using the custom column feature, BUT the colon ":" is part of the regex language and my non-existant regex skills can't figure out how to tell it to
1. Take everything before the ':' and copy to #maintitle
2. Take everything after the ': ' and copy to #subtitle

Workarounds such as manually separating the subtitle into comments or another column promotes inconsistency and incompleteness that doesn't work for me.

Any help is greatly appreciated, assume I know nothing about Regex. Reading the tutorials and absorbing them are two different things.

[theducks]

Originally Posted by racergirl76

I've been combing these forums for a week looking for a solution and am now admitting defeat.

I stongly prefer the Title field contain the full (long) title of a book:
"Maintitle of Book: Subtitle aka Strapline"

For more effencient use of the title contents for writing to disc/saving, templates, and for plugboards, I need to parse the title into two userdefined columns
"#maintitle" & "#subtitle"

So, I tried using the custom column feature, BUT the colon ":" is part of the regex language and my non-existant regex skills can't figure out how to tell it to
1. Take everything before the ':' and copy to #maintitle
2. Take everything after the ': ' and copy to #subtitle

Workarounds such as manually separating the subtitle into comments or another column promotes inconsistency and incompleteness that doesn't work for me.

Any help is greatly appreciated, assume I know nothing about Regex. Reading the tutorials and absorbing them are two different things.

Use the Search and replace tool of the bulk metadata edit against only those books with the : REGEX MODE

search field: title
search for (.+?)\:(.+?)
Destination will be done in 2 passes
destination Pass1: #maintitle
replace with: \1

destination Pass2: #subtitle
replace with: \2

[racergirl76]

Thank you, and that does work for text based columns. I had seen a similar solution in post:
https://www.mobileread.com/forums/sho...d.php?t=265061

I'm trying to make it more automated by using the 'column built from other columns' feature. What I was hoping for was to input a template into the make column from other columns for #maintitle(no colon) and #subtitle. Then have Calibre automatically save the book based on a template using the truncated #maintitle column as part of the folder name & file name.

I tried several templates for the custom column but don't know what I'm doing. such as
#maintitle = contains(field('title')([^:]*))
#subtitle = contains(field('title')([^:]*)re(field('title')

somewhere in these forums someone said to split the title into two columns, which we have achieved. But that means I have to manually run that search & replace, and then resave the books to the library based on another template and action.

Thank you for your assistance

[eschwartz]

This will get you the first portion (before the ":")

program:

re(
    field('title'),
    ':.*',
    ''
)

Alternatively, "cheat" by using list_item() and pretending it is a ":"-separated list:

program:

list_item(
    field('title'),
    0,
    ':'
)

...

Personally, I think this is exactly what custom columns named "#subtitle" are for, but you are the boss...