Regex: How to dynamically get words after the first word and not the last word in a '_' separated string? - regex

Working on a migrations class in php.
If I have a string like this:
create_users_roles_table
and I want to get the words between the first and the last word correctly, plus being able to get the word correct if there's only one word inbetween like:
create_users_table
How do I go about that?
I've done:
(\B)_([a-zA-Z]+)_?([a-zA-Z]+)_table
and that works fine when I do create_users_roles_table
and produces users and roles.
But when only doing create_users_table it produces user and s.
Obviously I need it to produce only users.
Anyone?


I think it should read
(\B)_([a-zA-Z]+)_?([a-zA-Z]+)?_table
But this won't work if there are three words in between. I'd suggest stripping the words and then splitting them separately, since I don't think regular expressions can handle variable number of capture groups.
If you can be sure of how many words there can be, you can always hard code this. For tree or less words you can use
(\B)_([a-zA-Z]+)(?:_([a-zA-Z]+))?(?:_([a-zA-Z]+))?_table

Related

Regular Expression: Two words in any order but with a string between?

I want to use positive lookaheads so that RegEx will pick up two words from two different sets in any order, but with a string between them of length 1 to 20 that is always in the middle.
It also is already case insensitive, allow for any number of characters including 0 before the first word found and the same after the second word found - I am unsure if it is more correct to terminate in $.
Without the any order matching I am so far as:
(?i:.*(new|launch|releas)+.{1,20}(product1|product2)+.*)
I have attempted to add any order matching with the following but it only picks up the first word:
(?i:.*(?=new|launch|releas)+.{1,20}(?=product1|product2)+.*)
I thought perhaps this was because of the +.{1,20} in the middle but I am unsure how it could work if I add this to both sets instead, as for instance this could cause a problem if the first word is the very first part of the source text it is parsing, and so no character before it.
I have seen example where \b is used for lookaheads but that also seems like it may cause a problem as I want it to match when the first word is at the start of the source text but also when it is not.
How should I edit my RegEx here please?

Regex to find X words only when a word doesn't exist

I'm trying to do some code refactoring and as I'm doing quite a lot I'm using WebStorm's regex find in files to see which files still need refactoring.
I know this (?:^|(?=[^']).\b)(this.user|this.isVatRegistered|showStatsInNet)\b will show all files with one of those bits of code in.
And according to this post: Match string that doesn't contain a specific word ^(?!.*UserMixin).*$ should do a negative look ahead to match only when that word doesn't exist.
My problem is I don't know how to combine them. Would someone be able to provide some guidance please?
I've tried combining like so: (?:^|(?=[^']).\b)(?!.*UserMixin)(this.user|this.isVatRegistered|showStatsInNet)\b but to no avail.
TL;DR How do I match on X number of words only when another word isn't present?

You have to work with a negative lookahead then try to match those sub-strings:
\A(?![\d\D]*?UserMixin)[\d\D]*?\b(?:this\.(?:user|isVatRegistered)|showStatsInNet)\b
This would be time consuming though since there are two [\d\D]*? occurrences that will move the cursor character by character to the end of file content.

Validating a list using Regex

I have been asked to help sort out a system that validates some returned MS Excel forms.
A Python program already exists that takes a returned Excel form, and another MS Excel workbook with looks much like the form, but the fields are filled with Regexes.
The Python code then validates the form by testing the returned form, against the Regexes in turn from the Regex form.
This all works as expected, and pumps out a workbook with a list of problems where a match doesn't occur.
However the validation wasn't always returning results as expected and I was asked to try sorting it out.
I have been reviewing the regexes against a document describes what the valid responses in the form should be. I can cope with most of them, but a couple of them got me to thinking. These are ones where the valid entry in the form is a list of items. E.g. a list of words seperated by commas or newlines.
Everytime I come across one of these I have been using the following approach:
^[A-Z]{0,10}((, *|\n)[A-Z]{0,10})*$
So this will match the first uppercase word up to 10 letters, then the rest of the list with each entry preceeded by a , or <CR>. It works, but I wonder if there is a better way? The reason I am thinking this is because the matching pattern for each list entry has to be in the regex twice. So if a problem is spotted, it has to be corrected in two places.
Is there a better way?

Use
^\b((^|, *|\n)[A-Z]{1,10})+$
It makes sure the text starts with a word character (i.e. a-zA-Z0-9_) by checking for a word boundary. Thus preventing the text to start with , or an empty line.
Then, repeating at least once, there should be a line beginning with one of
Start of text
A comma followed by any number of spaces
a newline
then, at least one, at the most ten, uppercase characters.
The first start alternative is obviously only possible for the start of the line, the second for intermediate words and the final for the last word on a line.
See it here at regex101.

Regular expression for rest of line after first x characters

I have a bunch of lines with IDs as the first six characters, and data I don't need after. Is there a way to identify everything after the ID section so Find and Replace can replace it with whitespace?

/.{6}\K.*//
If you want something more specific, please be more specific in your question.

'Looping' Through a Repeating Substring with Regex

The general problem:
I've got lot of data I'm trying to clean up then parse. Each line is really long, but they all have the same structure. It starts with one unique substring, followed by a second unique substring, followed by a substring that repeats about 20 times.
So it's: String A, String B, String C, String C, String C, etc. Every line is in that format.
At the start of String A is an ID, just a unique six digit number. I'm trying to insert that ID at the beginning of String B and all of the String C's.
String C is the problem. I can write regex's for each of the ID, B, and C, but trying to insert the captured ID into all the C's fails. It only works on the last one. That's actually the correct behavior here, but I'm pretty sure there is a way to to treat String C so that it will act like each instance of the substring is separate. And the regex runs over it again and again.
I tried using '\G' syntax but I can't seem to make it work.
So here's a specific example using some massively abridged sample data:
['sample_id':121084,[122,'southwest',7.23,[[['station_01',[1]],['station_02',[1]], ['station_03',[22]],['station_04',[49]],['station_05',[1]],['station_06',[4]],['station_07',[101]],['station_08',[22]]]],[[['run':133225,'marker':'SAM',[[['substation_01',[1]],['substation_02',[3]],['substation_03',[16]],['substation_04',[15]],['substation_05',[14]],['substation_06',[6]],['substation_07',[41]],['substation_08',[19]],['substation_09',[13]],['substation_10',[1]],['substation_11',[13]],['substation_12',[1]]]],'TK',22,34,127],['run':608049,'marker':'TIM',[[['substation_01',[12]],['substation_02',[6]],['substation_03',[17]],['substation_04',[11]],['substation_05',[1]],['substation_06',[6]],['substation_07',[5]],['substation_08',[19]]]],'TM',21,21,966],['run':445801,'marker':'RON',[[['substation_01',[5]],['substation_02',[5]],['substation_03',[6]],['substation_04',[11]],['substation_05',[1]],['substation_06',[15]],['substation_07',[11]],['substation_08',[16]],['substation_09',[1]],['substation_10',[13]],['substation_11',[3]]]],'TR',12,33,521],['run':142278, etc...
Just a note: The only difference between String B and all the String Cs is the number of brackets, but that's actually useful once I start parsing this out (ultimately it'll all be JSON).
What I'm trying to get is:
['sample_id':121084,[122,'southwest',7.23,[[['station_01',[1]],['station_02',[1]],['station_03',[22]],['station_04',[49]],['station_05',[1]],['station_06',[4]],['station_07',[101]],['station_08',[22]]]],[[['sample_id':121084,'run':133225,'marker':'SAM',[[['substation_01',[1]],['substation_02',[3]],['substation_03',[16]],['substation_04',[15]],['substation_05',[14]],['substation_06',[6]],['substation_07',[41]],['substation_08',[19]],['substation_09',[13]],['substation_10',[1]],['substation_11',[13]],['substation_12',[1]]]],'TK',22,34,127],['sample_id':121084,'run':608049,'marker':'TIM',[[['substation_01',[12]],['substation_02',[6]],['substation_03',[17]],['substation_04',[11]],['substation_05',[1]],['substation_06',[6]],['substation_07',[5]],['substation_08',[19]]],'TM',21,21,966],['sample_id':121084,'run':445801,'marker':'RON',[[['substation_01',[5]],['substation_02',[5]],['substation_03',[6]],['substation_04',[11]],['substation_05',[1]],['substation_06',[15]],['substation_07',[11]],['substation_08',[16]],['substation_09',[1]],['substation_10',[13]],['substation_11',[3]]],'TR',12,33,521],['sample_id':121084, etc...
In the latter text block each substring now begins with the ID 'sample_id':121084 (I bolded it to make it slightly easier to see what's going on).
Here's the Regex that gets me up through String C.
\[('sample_id':\d{6},)(?:.+\]\]\],\[\[)\[(.+?\d\],)\[(.+?\d\],)
So I'm trying to insert that first capture group ($1) in front of the second group, then the third group over and over and over (about 20x). If I repeat the last bit, I end up killing all but one of the C Strings, which again, I believe to be the 'proper' behavior. I'm trying to figure out how to get around that.
It's a mess I know. But each of those is just one line, and I've got doc after doc that'll have 100 or so lines like that. So a regex that doesn't break up the lines seems best.
I went over this page a few times trying to engineer a solution, but again, I couldn't make the \G syntax work here.
Collapse and Capture a Repeating Pattern in a Single Regex Expression
Should mention I'm trying to do this in Sublime Text 2. Thanks for any help.