A lookbehind is a part of the regular expression standard.
Questions tagged [lookbehind]
385 questions
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RegEx that removes XHTML line breaks appearing before block-level tags
I need a RegEx that finds extraneous
tags that occur before block tags, leaving all other
tags intact. Here's the text I am searching:
tags that occur before block tags, leaving all other
tags intact. Here's the text I am searching:
some text
some more text
However, when using the…some more text
Matt Miller
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python regex with conditional lookbehind
I'm looking for substring starting with @ and ending with the first \s occurrence.
It's necessary to have @ at the beginning of the string or after space.
Example: @one bla bla bla @two @three@four #@five
Result: @one, @two, @three@four
I end up…
qubblr
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How Can I Use Look-Ahead and Look-Behind to Create a Custom Boundary Matcher?
I want to split a String at the word boundaries using Scanner. Normally, this would be done like this:
Scanner scanner = new Scanner(...).useDelimiter("\\b");
The problem is that my definition of "word" character is a tiny bit different from the…
rolve
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Regex using Negative lookbehind and Negative lookahead assertion
Possible Duplicate:
Regex matching left single quotation outside the double quotations
First Note:
&ldquo - left double quote (")
&rdquo - right double quote (")
&lsquo - left single quote (')
&rsquo - right single quote (')
I need to match all…
neo
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Regex lookbehind assertion issue
this is my current regex:
(?<=[\$T|\s|\p{P}|\$%\$%])sampleString
I want to match all sampleString in my richtextBox
and some instance of sample string in my richtextBox is something like this :
$TsampleString
$%$%sampleString
The problem is that…
neo
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3 answers
Fixed Length Regex Required?
I have this regex that uses forward and backward look-aheads:
import re
re.compile(")|(?<=")
I'm trying to port it from C# to Python but keep getting the error
look-behind requires fixed-width pattern
Is it possible…
Chad
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Extract a portion of text using RegEx
I would like to extract portion of a text using a regular expression. So for example, I have an address and want to return just the number and streets and exclude the rest:
2222 Main at King Edward Vancouver BC CA
But the addresses varies in format…
Jaime
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How to capture lookbehind using java
I am trying to capture text that is matched by lookbehind.
My code :
private static final String t1="first:\\\w*";
private static final String t2="(?<=\\w+)=\\".+\\"";
private static final String t=t1+'|'+t2;
Pattern p=Pattern.compile(t);
Matcher…
Joseph
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How to extract content in between an opening and a closing bracket?
I am trying to split a string into an array of text contents which each are present within the [@ and ] delimiters. Just characters in between [@and ] are allowed to match. Being provided with a string like ...
const stringA = '[@Mary James],…
Sonali
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In regular expressions What is variable-length lookbehind-assertion?
I copied a statement that aims to convert a string into Camel Case in Octave. The code is as following.
function camelStr = stringcamelcase (str)
camelStr = lower(str)
idx = regexp([' ' camelStr], '(?<=\s+)\S', 'start') -1;
camelStr(idx)…
LudgerSB
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Look-behind issue with java regex. Look-behind group does not have an obvious maximum length
I need to match sequence='999' inside a tag in a xml document using Java RegEx (xml parser is not an option).
Snippet of the xml:
user2287359
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LookBehind - Find string occuring after a pattern
I need help regarding a regex Query :-
C: - total 79.45 Gb - used: 33.82 Gb (43%) - free 45.63 Gb (57%)
This is my sample text . I want to find the %usage of used disk . i.e 43% in my case .
I am using lookbehind to find the occurrences after…
animo3991
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how to match any string but not a string that starts with slash?
how to match any string but not a string that starts with a slash?
I'm using node js regex
that was my try but it didn't work
(?!\/s).*
Engineer Passion
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1 answer
JavaScript regex with positive lookbehind emulation
I am trying to create a regex that will extract the bold portion from a Flickr URL.
I want the string between www.flickr.com/photos/ and /.
https://www.flickr.com/photos/annaheimkreiter/14785981533/in/explore-2014-07-28
…
CodeToad
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Understanding lookbehind
I put in online testers the regular expression => .{3}(?<=USD\d{3}) and Subject string => USD100 and this returns 100.
I'd like to know is how the regex engine works in this case?
How the regex engine returns this 100?
Regular Expression:
…
