I want to extract excerpt from a long string using Regular expression
Example string: "" Is it possible that Germany, which beat Argentina 1-0 today to win the World Cup, that will end up as a loser in terms of economic growth? ""
String to search: " that "
Expected result from regex
" possible that Germany "
" rd Cup, that will end "
I want to search the desired text from the string with -9 and +9 characters from the forward and the backward of the occurence of the searched string. Search string can occur multiple times within the given string.
I am working on an iOS app
using iOS 7.
I have so far created this expression with my little knowledge about reguler expressions but not able to get desired result from that
" (.){0,9} (that) {0,9} "
Remove the spaces in your regex. If you want to capture the matched ones. Then enclose the pattern within capturing groups (ie, ()),
.{9}that.{9}
OR
(?:.{9}|.{0,9})that(?:.{9}|.{0,9})
DEMO
Make the preceding and following characters as optional to match the line which looks like that will change history
Well, in your expression you were just missing the second "." and maybe the "?" for spaces.
.{0,9} ?that ?.{0,9}
Try that.
You can add ( ) for making groups if you want. I added the "?" to make it comply with your other example:
" that will change history"
Related
I have a list of strings like this:
/soccer/poland/ekstraklasa-2008-2009/results/
/soccer/poland/orange-ekstraklasa-2007-2008/results/
/soccer/poland/orange-ekstraklasa-youth-2010-2011/results/
From each string I want to take a middle part resulting in respectively:
ekstraklasa
orange ekstraklasa
orange ekstraklasa youth
My code here does the job but it feels like it can be done in fewer steps and probably with regex alone.
name = re.search('/([-a-z\d]+)/results/', string).group(1) # take the middle part
name = re.search('[-a-z]+', name).group() # trim numbers
if name.endswith('-'):
name = name[:-1] # trim tailing `-` if needed
name = name.replace('-', ' ')
Can anyone see how make it better?
This regex should do the work:
/(?:\/\w+){2}\/([\w\-]+)(?:-\d+){2}/
Explanation:
(?:\/\w+){2} - eat the first two words delimited by /
\/ - eat the next /
([\w\-]+)- match the word characters of hyphens (this is what we're looking for)
(?:-\d+){2} - eat the hyphens and the numbers after the part we're looking for
The result is in the first match group
I cant test it because i am not using python, but i would use an Expression like
^(/soccer/poland/)([a-z\-]*)(.*)$
or
^(/[a-z]*/[a-z]*/)([a-z\-]*)(.*)$
This Expressen works like "/soccer/poland/" at the beginning, than "everything with a to z (small) or -" and the rest of the string.
And than taking 2nd Group!
The Groups should hold this Strings:
/soccer/poland/
orange-ekstraklasa-youth-
2010-2011/results/
And then simply replacing "-" with " " and after that TRIM Spaces.
PS: If ur Using regex101.com e.g., u need to escape / AND just use one Row of String!
Expression
^(\/soccer\/poland\/)([a-z\-]*)(.*)$
And one Row of ur String.
/soccer/poland/orange-ekstraklasa-youth-2010-2011/results/
If u prefere to use the Expression not just for soccer and poland, use
^(\/[a-z]*\/[a-z]*\/)([a-z\-]*)(.*)$
I need to hide part of the string. Hide all before some ending part.
It easy to implement by regexp like this:
replace("123-134-04", ".(?=.*-)", " ")
replace any symbol if future part of string contains "-".
So result is: " -04"
It is important to keep spaces.
But, I can't use lookahead or lookbehind.
I can catch the group before ending part, but how to replace this for right number of spaces?
Or maybe some other ways to resolve this with regex?
Tnanks in advance!
If the number of to be replaced characters does not differ too much, and you have a means to match the part to be preserved, you could run through a series of search and replace:
replace("12-14-04", "^.{5}(-[^-]+)$", " \1")
replace("123-134-04", "^.{7}(-[^-]+)$", " \1")
replace("adfasd-adf-da7474-04", "^.{17}(-[^-]+)$", " \1")
Or you do:
split the string at the position, where the to be preserved part begins,
run the replace("ALL OF THIS SHOULD BECOME BLANKS", ".", " ") on the first part, and
join them up again.
I've been working on this for a while, but it's beyond my understanding of regex.
I'm using Yahoo Pipes on an RSS, and I want to create hashtags from titles; so, I'd like to remove space from everything between quotes, but, if there's a colon within the quotes, I only want the space removed between the words before the colon.
And, it would be great if I could also capture the unspaced words as a group, to be able to use: #$1 to output the hashtag in one step.
So, something like:
"The New Apple: Worlds Within Worlds" Before We Begin...
Could be substituted like #$1 - with this result:
"#TheNewApple: Worlds Within Worlds" Before We Begin...
After some work, I was able to come up with, this regex:
\s(?=\s)?|(‘|’|(Review)|:.*)
("Review" was a word that often came before colons and wouldn't be stripped, if it were later in the title; that's what that's for, but I would like to not require that, to be more universal)
But, it has two problems:
I have to use multiple steps. The result of that regex would be:
"TheNewApple: Worlds Within Worlds" Before We Begin...
And I could then add another regex step, to put the hash # in front
But, it only works if the quotes are first, and I don't know how to fix that...
You can do this all in one step with regex, with a caveat. You run into problems with a repeated capturing group because only the last iteration is available in the replacement string. Searching for ( (\w+))+ and replacing with $2 will replace all the words with just the last match - not what we want.
The way around this is to repeat the pattern an arbitrary number of times that will suffice for your use. Each separate group can be referenced.
Search: "(\w+)(?: (\w+))?(?: (\w+))?(?: (\w+))?(?: (\w+))?(?: (\w+))?
Replace: "#$1$2$3$4$5$6
This will replace up to 6-word titles, exactly as you need them. First, "(\w+) matches any word following a quote. In the replacement string, it is put back as "#$1, adding the hashtag. The rest is a repeated list of (?: (\w+))? matches, each matching a possible space and word. Notice the space is part of a non-capturing group; only the word is part of the inner capture group. In the replacement string, I have $1$2$3$4$5$6, which puts back the words, without the spaces. Notice that a colon will not match any part of this, so it will stop once it hits a colon.
Examples:
"The New Apple: Worlds Within Worlds" Before We Begin...
"The New Apple" Before We Begin...
"One: Two"
only "One" word
this has "Two Words"
"The Great Big Apple Dumpling"
"The Great Big Apple Dumpling Again: Part 2"
Results:
"#TheNewApple: Worlds Within Worlds" Before We Begin...
"#TheNewApple" Before We Begin...
"#One: Two"
only "#One" word
this has "#TwoWords"
"#TheGreatBigAppleDumpling"
"#TheGreatBigAppleDumplingAgain: Part 2"
You can match the text with
"([^:]*)(.*?)"(.*)
then use some programming language to output the result like this:
'"#' + removeSpace($1) + $2 + '"' + $3
I have no idea what language you're using, but this seems like a poor choice for regex. In Python I'd do this:
# Python 3
import re
titles = ['''"The New Apple: Worlds Within Worlds" Before We Begin...''',
'''"Made Up Title: For Example Only" So We Can Continue...''']
hashtagged_titles = list()
for title in titles:
hashtagme, *restofstring = title.split(":")
hashtag = '"#'+hashtagme[1:].translate(str.maketrans('', '', " "))
result = "{}:{}".format(hashtag, restofstring)
hashtagged_titles.append(result)
Do a global search for
\ (?=.*:)
Replaced with nothing. Example
You'll need a second search on the results of that if you want to capture "TheNewApple" as a single word.
How to get following result using Regex into C#.
string input = "<P>With effect from <<Effective Date>>, the xyz is amended as follows:</P><P>The xyz will xyz the Insured for Claims including x amount Costs or Legal Fees which arise out of or in xyz with <<Description of xyz/abc>>.</P><P>All other terms and conditions of the dddd remain unchanged.</P>";
Regex r = new Regex("Regular expression needed!!!");
So i am looking for following field collection using Regex (Starting with special charachter << AND ending with >>)
<<Effective Date>>
<<Description of xyz/abc>>
Usually when questions like this are asked some effort needs to be shown instead of creating a new regular expression object stating Regular expression needed!!! inside the pattern. So please take consideration to state the exact problem with at least some effort on what you have attempted next time.
To get you started, you can use the following.
foreach (Match m in Regex.Matches(input, #"<<[^>]*>>"))
Console.WriteLine(m.Value);
Explanation:
<< # '<<'
[^>]* # any character except: '>' (0 or more times)
>> # '>>'
Working Demo
Here are a few references to start your path of learning regular expressions.
Regular-Expressions.info
Quick-Start: Regex Cheat Sheet
How do I get the substring " It's big \"problem " using a regular expression?
s = ' function(){ return " It\'s big \"problem "; }';
/"(?:[^"\\]|\\.)*"/
Works in The Regex Coach and PCRE Workbench.
Example of test in JavaScript:
var s = ' function(){ return " Is big \\"problem\\", \\no? "; }';
var m = s.match(/"(?:[^"\\]|\\.)*"/);
if (m != null)
alert(m);
This one comes from nanorc.sample available in many linux distros. It is used for syntax highlighting of C style strings
\"(\\.|[^\"])*\"
As provided by ePharaoh, the answer is
/"([^"\\]*(\\.[^"\\]*)*)"/
To have the above apply to either single quoted or double quoted strings, use
/"([^"\\]*(\\.[^"\\]*)*)"|\'([^\'\\]*(\\.[^\'\\]*)*)\'/
Most of the solutions provided here use alternative repetition paths i.e. (A|B)*.
You may encounter stack overflows on large inputs since some pattern compiler implements this using recursion.
Java for instance: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6337993
Something like this:
"(?:[^"\\]*(?:\\.)?)*", or the one provided by Guy Bedford will reduce the amount of parsing steps avoiding most stack overflows.
/(["\']).*?(?<!\\)(\\\\)*\1/is
should work with any quoted string
"(?:\\"|.)*?"
Alternating the \" and the . passes over escaped quotes while the lazy quantifier *? ensures that you don't go past the end of the quoted string. Works with .NET Framework RE classes
/"(?:[^"\\]++|\\.)*+"/
Taken straight from man perlre on a Linux system with Perl 5.22.0 installed.
As an optimization, this regex uses the 'posessive' form of both + and * to prevent backtracking, for it is known beforehand that a string without a closing quote wouldn't match in any case.
This one works perfect on PCRE and does not fall with StackOverflow.
"(.*?[^\\])??((\\\\)+)?+"
Explanation:
Every quoted string starts with Char: " ;
It may contain any number of any characters: .*? {Lazy match}; ending with non escape character [^\\];
Statement (2) is Lazy(!) optional because string can be empty(""). So: (.*?[^\\])??
Finally, every quoted string ends with Char("), but it can be preceded with even number of escape sign pairs (\\\\)+; and it is Greedy(!) optional: ((\\\\)+)?+ {Greedy matching}, bacause string can be empty or without ending pairs!
An option that has not been touched on before is:
Reverse the string.
Perform the matching on the reversed string.
Re-reverse the matched strings.
This has the added bonus of being able to correctly match escaped open tags.
Lets say you had the following string; String \"this "should" NOT match\" and "this \"should\" match"
Here, \"this "should" NOT match\" should not be matched and "should" should be.
On top of that this \"should\" match should be matched and \"should\" should not.
First an example.
// The input string.
const myString = 'String \\"this "should" NOT match\\" and "this \\"should\\" match"';
// The RegExp.
const regExp = new RegExp(
// Match close
'([\'"])(?!(?:[\\\\]{2})*[\\\\](?![\\\\]))' +
'((?:' +
// Match escaped close quote
'(?:\\1(?=(?:[\\\\]{2})*[\\\\](?![\\\\])))|' +
// Match everything thats not the close quote
'(?:(?!\\1).)' +
'){0,})' +
// Match open
'(\\1)(?!(?:[\\\\]{2})*[\\\\](?![\\\\]))',
'g'
);
// Reverse the matched strings.
matches = myString
// Reverse the string.
.split('').reverse().join('')
// '"hctam "\dluohs"\ siht" dna "\hctam TON "dluohs" siht"\ gnirtS'
// Match the quoted
.match(regExp)
// ['"hctam "\dluohs"\ siht"', '"dluohs"']
// Reverse the matches
.map(x => x.split('').reverse().join(''))
// ['"this \"should\" match"', '"should"']
// Re order the matches
.reverse();
// ['"should"', '"this \"should\" match"']
Okay, now to explain the RegExp.
This is the regexp can be easily broken into three pieces. As follows:
# Part 1
(['"]) # Match a closing quotation mark " or '
(?! # As long as it's not followed by
(?:[\\]{2})* # A pair of escape characters
[\\] # and a single escape
(?![\\]) # As long as that's not followed by an escape
)
# Part 2
((?: # Match inside the quotes
(?: # Match option 1:
\1 # Match the closing quote
(?= # As long as it's followed by
(?:\\\\)* # A pair of escape characters
\\ #
(?![\\]) # As long as that's not followed by an escape
) # and a single escape
)| # OR
(?: # Match option 2:
(?!\1). # Any character that isn't the closing quote
)
)*) # Match the group 0 or more times
# Part 3
(\1) # Match an open quotation mark that is the same as the closing one
(?! # As long as it's not followed by
(?:[\\]{2})* # A pair of escape characters
[\\] # and a single escape
(?![\\]) # As long as that's not followed by an escape
)
This is probably a lot clearer in image form: generated using Jex's Regulex
Image on github (JavaScript Regular Expression Visualizer.)
Sorry, I don't have a high enough reputation to include images, so, it's just a link for now.
Here is a gist of an example function using this concept that's a little more advanced: https://gist.github.com/scagood/bd99371c072d49a4fee29d193252f5fc#file-matchquotes-js
here is one that work with both " and ' and you easily add others at the start.
("|')(?:\\\1|[^\1])*?\1
it uses the backreference (\1) match exactley what is in the first group (" or ').
http://www.regular-expressions.info/backref.html
One has to remember that regexps aren't a silver bullet for everything string-y. Some stuff are simpler to do with a cursor and linear, manual, seeking. A CFL would do the trick pretty trivially, but there aren't many CFL implementations (afaik).
A more extensive version of https://stackoverflow.com/a/10786066/1794894
/"([^"\\]{50,}(\\.[^"\\]*)*)"|\'[^\'\\]{50,}(\\.[^\'\\]*)*\'|“[^”\\]{50,}(\\.[^“\\]*)*”/
This version also contains
Minimum quote length of 50
Extra type of quotes (open “ and close ”)
If it is searched from the beginning, maybe this can work?
\"((\\\")|[^\\])*\"
I faced a similar problem trying to remove quoted strings that may interfere with parsing of some files.
I ended up with a two-step solution that beats any convoluted regex you can come up with:
line = line.replace("\\\"","\'"); // Replace escaped quotes with something easier to handle
line = line.replaceAll("\"([^\"]*)\"","\"x\""); // Simple is beautiful
Easier to read and probably more efficient.
If your IDE is IntelliJ Idea, you can forget all these headaches and store your regex into a String variable and as you copy-paste it inside the double-quote it will automatically change to a regex acceptable format.
example in Java:
String s = "\"en_usa\":[^\\,\\}]+";
now you can use this variable in your regexp or anywhere.
(?<="|')(?:[^"\\]|\\.)*(?="|')
" It\'s big \"problem "
match result:
It\'s big \"problem
("|')(?:[^"\\]|\\.)*("|')
" It\'s big \"problem "
match result:
" It\'s big \"problem "
Messed around at regexpal and ended up with this regex: (Don't ask me how it works, I barely understand even tho I wrote it lol)
"(([^"\\]?(\\\\)?)|(\\")+)+"