I have a list of the following numbers and want a Regular expression that matches when a number is not in the list.
0,1,2,3,4,9,11,12,13,14,15,16,18,19,250
I have written the following REGEX statement.
^(?!.*(0|1|2|3|4|9|11|12|13|14|15|16|18|19|250)).*$
The problem is that it correctly gives a match for 5,6,7,8 etc but not for 17 or 251 for example.
I have been testing this on the online REGEX simulators.
This should resolve your issue..
^(?!\D*(0|1|2|3|4|9|11|12|13|14|15|16|18|19|250)\b).*$
In your earlier regex you were basically saying eliminate all numbers that start with 0/1/2/3/4/9!
So your original regex would actually match 54/623/71/88 but not the others. Also the 11-19 and 250 in the list were rendered useless.
Although as others have I would also recommend you to not use regex for this, as I believe it is an overkill and a maintenance nightmare!
Also an extra note "Variable length look arounds are very inefficient too" vs regular checks.
I would do \b\d+\b to get each number in the string and check if they are in your list. It would be way faster.
You can use the discard technique by matching what you do not want and capturing what you really want.
You can use a regex like this:
\b(?:[0-49]|1[1-689]|250)\b|(\d+)
Here you can check a working demo where in blue you have the matches (what you don't want) and in green the content you want. Then you have to grab the content from the capturing group
Working demo
Not sure what regex engine you are using, but here I created a sample using java:
https://ideone.com/B7kLe0
Related
I'm trying to see if its possible to extend an existing arbitrary regex by prepending or appending another regex to match within matches.
Take the following example:
The original regex is cat|car|bat so matching output is
cat
car
bat
I want to add to this regex and output only matches that start with 'ca',
cat
car
I specifically don't want to interpret a whole regex, which could be quite a long operation and then change its internal content to match produce the output as in:
^ca[tr]
or run the original regex and then the second one over the results. I'm taking the original regex as an argument in python but want to 'prefilter' the matches by adding the additional code.
This is probably a slight abuse of regex, but I'm still interested if it's possible. I have tried what I know of subgroups and the following examples but they're not giving me what I need.
Things I've tried:
^ca(cat|car|bat)
(?<=ca(cat|car|bat))
(?<=^ca(cat|car|bat))
It may not be possible but I'm interested in what any regex gurus think. I'm also interested if there is some way of doing this positionally if the length of the initial output is known.
A slightly more realistic example of the inital query might be [a-z]{4} but if I create (?<=^ca([a-z]{4})) it matches against 6 letter strings starting with ca, not 4 letter.
Thanks for any solutions and/or opinions on it.
EDIT: See solution including #Nick's contribution below. The tool I was testing this with (exrex) seems to have a slight bug that, following the examples given, would create matches 6 characters long.
You were not far off with what you tried, only you don't need a lookbehind, but rather a lookahead assertion, and a parenthesis was misplaced. The right thing is: Put the original pattern in parentheses, and prepend (?=ca):
(?=ca)(cat|car|bat)
(?=ca)([a-z]{4})
In the second example (without | alternative), the parentheses around the original pattern wouldn't be required.
Ok, thanks to #Armali I've come to the conclusion that (?=ca)(^[a-z]{4}$) works (see https://regexr.com/3f4vo). However, I'm trying this with the great exrex tool to attempt to produce matching strings, and it's producing matches that are 6 characters long rather than 4. This may be a limitation of exrex rather than the regex, which seems to work in other cases.
See #Nick's comment.
I've also raised an issue on the exrex GitHub for this.
I am at the beginning of learning Regex, and I use every opportunity to understand how it's working. Currently I am trying to extract dates from a text file (which is in fact a vnt-file type from my mobile phone). It looks like following:
BEGIN:VNOTE
VERSION:1.1
BODY;ENCODING=QUOTED-PRINTABLE;CHARSET=UTF-8:18.07.=0A14.08.=0A15.09.=0A15.10.=
=0A13.11.=0A13.12.=0A12.01.=0A03.02. Grippe=0A06.03.=0A04.04.2015=0A0=
5.05.2015=0A03.06.2015=0A03.07.2015=0A02.08.2015=0A30.08.2015=0A28.09=
17.11.2017=0A
DCREATED:20171118T095601
X-IRMC-LUID:150
END:VNOTE
I want to extract all dates, so that the final list is like that:
18.07.
14.08.
15.09.
15.10.
and so on. If the date has also a year, it should also be displayed.
I almost found out how to detect the dates by the following regex:
.+(\d\d\.\d\d\.(2015|2016|2017)?).+
But it only detect very few of the dates. The result is this:
BEGIN:VNOTE
VERSION:1.1
15.10.
04.04.2015
30.08.2015
24.01.2016
DCREATED:20171118T075601
X-IRMC-LUID:150
END:VNOTE
Then I tried to add a question mark which makes the .+ not greedy, as far as I read in tutorials. Then the regex looks like:
.+?(\d\d\.\d\d\.(2015|2016|2017)?).+?
But the result is still not what I am looking for:
BEGIN:VNOTE
VERSION:1.1
21.03.20.04.18.05.18.06.18.07.14.08.15.09.15.10.
13.11.13.12.12.01.03.02.06.03.04.04.20150A0=
03.06.201503.07.201502.08.201530.08.20150A28.09=
28.10.201525.11.201528.12.201524.01.20160A
DCREATED:20171118T075601
X-IRMC-LUID:150
END:VNOTE
For someone who is familiar with regex I am pretty sure this is very easy to solve, but I don't get it. It's very confusing when you are new to regex. I tried to find a hint in some tutorials or stackoverflow posts, but all I found is this: Notepad++ how to extract only the text field which is needed?
But it doesn't work for me. I assume it might have something to do with the fact that my text file is not one single line.
I have my example on regex101 too.
I would be very thankful if maybe someone can give me a hint what else I can try.
Edit: I would like to detect the dates with the regex and as a result have a list with only the dates (maybe it is called substitute?)
Edit 2: Sorry for not mentioning it earlier: I just want to use the regex in e.g. Notepad++ or an online regex test website. Just to get the result of the dates and save the result in a new txt-file. I don't want to use the regex in an programming language. My apologies for not being precisely before.
Edit 3: The result should be a list with the dates, and each date in a new line:
I want to extract all dates, so that the final list is like that:
18.07.
14.08.
15.09.
15.10.
I suggest this pattern:
(?:.*?|\G)(\d\d\.\d\d\.(?:\d{4})?)
This makes use of the \G flag that, in this case, allows for multiple matches from the very start of the match without letting any single unmatched character in the text, thus allowing the removal of all but what's wanted.
If you want to remove the extra matches as well, add |.* at the end:
(?:.*?|\G)(\d\d\.\d\d\.(?:\d{4})?)|.*
regex101 demo
In N++, make sure the options underlined are selected, and that the cursor is at the beginning. In the picture below, I replaced then undid the replacement, only to show that matches were identified (16 replacements).
You can try using the following pattern:
\d{2}\.\d{2}\.(?:\d{4})?
This will match day.month dates of the form 18.07., but it also allows such a date to be followed by a four digit year, e.g. 18.07.2017. While it would be nice to make the pattern more restrictive, to avoid false fire matches, I do not see anything obvious which can be added to the above pattern. Follow the demo link below to see the pattern in action.
Demo
My college asked my to provide him with a regex that only matches if the test-string endswith
.rar or .part1.rar or part01.rar or part001.rar (and so on).
Should match:
foo.part1.rar
xyz.part01.rar
archive.rar
part3_is_the_best.rar
Should not match:
foo.r61
bar.part03.rar
test.sfv
I immediately came up with the regex \.(part0*1\.)?rar$. But this does match for bar.part03.rar.
Next I tried to add a negative look behind assertion: .*(?<!part\d*)\.(part\0*1\.)?rar$ That didn't work either, because look around assertions need to be fixed width.
Then I tried using a regex-conditional. But that didn't work either.
So my question: Can this even be solved by using pure regex?
An answer should either contain a link to regex101.com providing a working solution, or explain why it can't work by using pure regex.
You could use lookahead to verify the one case that fails your original regex (.rar with .part part that isn't 0*1) is discredited:
^(?!.*\.part0*[^1]\.rar$).*\.(part0*1\.)?rar$
See it in action
This is an old question, but here's another approach:
(?:\.part0*1\.rar|^(?<!\.)\w+\.rar)$
The idea is to match either:
A string that ends with .part0*1.rar (ie foo.part01.rar, foo.part1.rar, bar.part001.rar), OR
A string that ends with .rar and doesn't contain any other dots (.) before that.
Works on all your test cases, plus your extra foo.part19.rar.
https://regex101.com/r/EyHhmo/2
Hopefully someone can help me out. Been all over google now.
I'm doing some zone-ocr of documents, and want to extract some text with regex. It is always like this:
"Til: Name Name Name org.nr 12323123".
I want to extract the name-part, it can be 1-4 names, but "Til:" and "org.nr" is always before and after.
Anyone?
If you can't use capturing groups (check your documentation) you can try this:
(?<=Til:).*?(?=org\.nr)
This solution is using look behind and lookahead assertions, but those are not supported from every regex flavour. If they are working, this regex will return only the part you want, because the parts in the assertions are not matched, it checks only if the patterns in the assertions are there.
Use the pattern:
Til:(.*)org\.nr
Then take the second group to get the content between the parenthesis.
We used two different methods to reference external documents and Bugzilla bug numbers.
I'm now looking for a regular expression that matches these two possibilities of reference strings for convenient display and linking in the TortoiseSVN 1.6.16 log screen. First should be a bugzilla entry of the form [BZ#123], second is [some text and numbers], which has not to be converted into a url.
This can be matched with
\[BZ#\d+\]
and
\[.*?\]
My problem now is to concatenate those two match strings together. Usually this would be done by the regex (first|second), and I've done it this way:
(\[.*?\]|\[BZ#\d+\])
Unfortunately in this case TortoiseSVN seems to catch it all as the bug number because of the round braces. Even if I add a second expression which (according to the documentation) is meant to be used to extract the issue number itself, this second expression is supposed to be ignored:
(\[.*?\]|\[BZ#\d+\])
\[BZ#(\d+)\]
In this case TortoiseSVN displays the bug and document references correctly in the separate column, but uses them completely for the bugtracker url, which is of course not working:
https://mybugzillaserver/show_bug.cgi?id=[BZ#949]
BTW, Mercurial uses a better way by using {1}, {2}, ... as the placeholder in URLs.
Has anybody an idea how to solve this problem?
EDIT
In short: We have used [BZ#123] as bug number references and [anytext] as references to other (partly non-electronic) documents. We would like to have both patterns listed in TortoiseSVN's extra column, but only the bug number from the first part shpuld be used as %BUGID% in the URL string.
EDIT 2
Supposedly TortoiseSVN cannot handle nested regex groups (round braces), so this question doesn't have any satisfactory answer at the moment.
I'm not familiar with TortoiseSVN regex, but what it looked like the problem was that the first piece of the regex ([.*?\]) would always match, so you would never even get to the part evaluating the second part, \[BZ#(\d+)\]
Try this one instead:
((?<=\[BZ#)\d+(?=\])|\[.*?\])
Explanation:
( #Opening group.
(?<=\[BZ#) #Look behind for a bugzilla placeholder.
\d+ #Capture just the digits.
(?=\]) #Look ahead for the closing bracket (probably not necessary.)
| #Or, if that fails,
\[.*?\] #Find all other placeholders.
) #Closing the group.
Edit: I've just looked at TortoiseSVN docs. You could also try to keep the Message part expression the same, but change the Bug-ID expression to:
(?<=\[BZ#)(\d+)(?=\])
Edit: ?<= represents a zero-width lookbehind. See http://www.regular-expressions.info/lookaround.html. It is possible that TortoiseSVN doesn't support lookbehinds.
What happens if you just use (\d+) for your Bug-ID expression?