Problem with (what I thought was) a simple regex

tguillemin

I want to capitalize the first letter of each line in a text. So, I came up with the following Find/Replace (Regular Expression)

Find : ^([a-z])

Replace with : \U$1

This works in Regex101 (Python flavor), but not in Editorial (I get a capital U at the beginning of each line starting with a lower case character)

Where did I go wrong ?

Thanks in advance

omz

Hmm, this doesn't work in Regex101 for me, and I've never heard of \U as an "uppercase modifier" (I'm not a regex expert though).

You can achieve the same effect using a Python script action with something like this in Editorial:

import re, workflow
text = workflow.get_input()
text = re.sub(r'^([a-z])', lambda m: m.group(1).upper(), text, flags=re.M)
workflow.set_output(text)

omz

Wait, it does work in Regex101 (no idea why it didn't previously), but I don't really know why, i.e. which regex feature/flavor is responsible for it. Anyway, I hope the script helps.

tguillemin

It woks nicely
Thank you very much, and thanks again for this app.

ccc

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. -- Jamie Zawinski, 1997

lines = '\n'.join(line[:1].upper() + line[1:] for line in lines.splitlines())

dgelessus

@ccc You might want to use .title() instead of .upper(). For Unicode characters that contain more than one letter (like the ﬁ ligature), .upper() does not do what you expect:

>>> s = "ﬁnish"
>>> s[0].upper() + s[1:]
'FInish'
>>> s[0].title() + s[1:]
'Finish'

To be fair, it's unlikely that you'll ever encounter a character like that in practice, but it doesn't hurt to use the proper method.

ccc

@dgelessus Watch out for those blank lines...

lines = '\n'.join(line[:1].title() + line[1:] for line in lines.splitlines()) + '\n'

Solves the ligature issue and deals gracefully with blank lines (except at end of file).

The regex approach does not handle leading ligatures but instead leaves them lowercase because the ﬁ ligature is not in [a-z].

tguillemin

@ccc said:

lines = '\n'.join(line[:1].title() + line[1:] for line in lines.splitlines()) + '\n'

I had not tried it with blank lines (in my file, it does not occur)
Nevertheless, I tried your solution - successfully - after inserting those blank lines.

Thank you. That will most certainly be useful some day…!