Saved Search/Regex Functions

[DyckBook]

Originally Posted by kovidgoyal

That's because builtin function are not simple standalone functions you can learn from, they use other calibre code, however if you want to see them look in function_replace.py in the calibre source code.

Thanks Kovid, I'll work on that.

[greenskye]

I'm looking for a method to convert numbers that use the european comma separated format (ex. 1.000,95) to the US version (ex 1,000.95)

Is this achievable with regex or via a search function?

[lomkiri]

Assuming all numbers are in european format (no one in US format):

find:
\d[,.\d]{2,}(?![^<>{}]*[>}])
function:
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs): 
    return match.group(0).replace('.', '§').replace(',', '.').replace('§',',')

Warning: if you have a mixture of numbers in both formats (US and european), they will be switched. In that case, you'll have to refine the selection to catch only european ones.

Note: all number with 3 or more positions will be catched (e.g. 1,2, or 1.2). If you want to be more selective, change "{2,} for what you want minus 1, e.g. {4,} if you want to catch starting from 5 positions (1.000 or 12,45)

Note: Integers as 100 or 234000 will be catched, but they won't be transformed.

Warning : numbers followed by 3 dots will be wrongly transformed : "They were 20..." will give "They were 20,,,"
It's wise to change them to ellipsis (…) prior to apply the conversion:
(\d)\.{3} ==> \1\u2026

[greenskye]

Spoiler:

Originally Posted by lomkiri

Assuming all numbers are in european format (no one in US format):

find:
\d[,.\d]{2,}(?![^<>{}]*[>}])
function:
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs): 
    return match.group(0).replace('.', '§').replace(',', '.').replace('§',',')

Warning: if you have a mixture of numbers in both formats (US and european), they will be switched. In that case, you'll have to refine the selection to catch only european ones.

Note: all number with 3 or more positions will be catched (e.g. 1,2, or 1.2). If you want to be more selective, change "{2,} for what you want minus 1, e.g. {4,} if you want to catch starting from 5 positions (1.000 or 12,45)

Note: Integers as 100 or 234000 will be catched, but they won't be transformed.

Warning : numbers followed by 3 dots will be wrongly transformed : "They were 20..." will give "They were 20,,,"
It's wise to change them to ellipsis (…) prior to apply the conversion:
(\d)\.{3} ==> \1\u2026

Thanks so much, it worked great!

I ended up using

find 1: (\d{1,3}[.,])+\d{1,}(?![^<>{}]*[>}])

find 2: \$(\d{1,3}[.,])+\d{1,}(?![^<>{}]*[>}])

The updated regex fixed the problem with trailing "." matches. I did a replace all with "find 1", and then ran it again with "find 2" to revert any US currencies accidentally caught. Couldn't figure out how to exclude them in first place (kept matching part of the currency number)

[lomkiri]

Originally Posted by greenskye

The updated regex fixed the problem with trailing "." matches

Mmmh, yes, of course, I forgot this case :-/. Good you thought about it :-)

I did a replace all with "find 1", and then ran it again with "find 2" to revert any US currencies accidentally caught. Couldn't figure out how to exclude them in first place (kept matching part of the currency number)

This one seems to be ok to exclude groups beginning with $ (and not selecting inside tags) :

(\$(?:\d{1,3}[.,])+)(*SKIP)(*F)|(<[^<>]*)(*SKIP)(*F)|(?:\d{1,3}[.,])+\d{1,}

Another way would have been to catch the currency in the regex, then it's easy to make the selection inside the function:

\$?(\d{1,3}[.,])+\d{1,}(?![^<>{}]*[>}])
function:
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    m = match.group(0)
    if m[0] == '$':
        return m
    else:        
        return m.replace('.', '§').replace(',', '.').replace('§',',')