I want to find and separate words in a title that has no spaces.
Before:
ThisIsAnExampleTitleHELLO-WORLD2019T.E.S.T.(Test)"Test"'Test'[Test]
After:
This Is An Example Title HELLO-WORLD 2019 T.E.S.T. (Test) [Test] "Test" 'Test'
I'm looking for a regular expression rule that can do the following.
I thought I'd identify each word if it starts with an uppercase letter.
But also preserve all uppercase words as not to space them into A L L U P P E R C A S E.
Additional rules:
Space a letter if it touches a number: Hello2019World Hello 2019 World
Ignore spacing initials that contain periods, hyphens, or underscores T.E.S.T.
Ignore spacing if between brackets, parentheses, or quotes [Test] (Test) "Test" 'Test'
Preserve hyphens Hello-World
C#
https://rextester.com/GAZJS38767
// Title without spaces
string title = "ThisIsAnExampleTitleHELLO-WORLD2019T.E.S.T.(Test)[Test]\"Test\"'Test'";
// Detect where to space words
string[] split = Regex.Split(title, "(?<!^)(?=(?<![.\\-'\"([{])[A-Z][\\d+]?)");
// Trim each word of extra spaces before joining
split = (from e in split
select e.Trim()).ToArray();
// Join into new title
string newtitle = string.Join(" ", split);
// Display
Console.WriteLine(newtitle);
Regular expression
I'm having trouble with spacing before the numbers, brackets, parentheses, and quotes.
https://regex101.com/r/9IIYGX/1
(?<!^)(?=(?<![.\-'"([{])(?<![A-Z])[A-Z][\d+?]?)
(?<!^) // Negative look behind
(?= // Positive look ahead
(?<![.\-'"([{]) // Ignore if starts with punctuation
(?<![A-Z]) // Ignore if starts with double Uppercase letter
[A-Z] // Space after each Uppercase letter
[\d+]? // Space after number
)
Solution
Thanks for all your combined effort in answers. Here's a Regex example. I'm applying this to file names and have exclude special characters \/:*?"<>|.
https://rextester.com/FYEVE73725
https://regex101.com/r/xi8L4z/1
Here is a regex which seems to work well, at least for your sample input:
(?<=[a-z])(?=[A-Z])|(?<=[0-9])(?=[A-Za-z])|(?<=[A-Za-z])(?=[0-9])|(?<=\W)(?=\W)
This patten says to make a split on a boundary of one of the following conditions:
what precedes is a lowercase, and what precedes is an uppercase (or
vice-versa)
what precedes is a digit and what follows is a letter (or
vice-versa)
what precedes and what follows is a non word character
(e.g. quote, parenthesis, etc.)
string title = "ThisIsAnExampleTitleHELLO-WORLD2019T.E.S.T.(Test)[Test]\"Test\"'Test'";
string[] split = Regex.Split(title, "(?<=[a-z])(?=[A-Z])|(?<=[0-9])(?=[A-Za-z])|(?<=[A-Za-z])(?=[0-9])|(?<=\\W)(?=\\W)");
split = (from e in split select e.Trim()).ToArray();
string newtitle = string.Join(" ", split);
This Is An Example Title HELLO-WORLD 2019 T.E.S.T. (Test) [Test] "Test" 'Test'
Note: You might also want to add this assertion to the regex alternation:
(?<=\W)(?=\w)|(?<=\w)(?=\W)
We got away with this here, because this boundary condition never happened. But you might need it with other inputs.
First few parts are similar to #revo answer: (?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}, additionally I add the following regex to space between number and letter: (?<=[a-z])(?=\d)|(?<=\d)(?=[a-z])|(?<=[A-Z])(?=\d)|(?<=\d)(?=[A-Z]) and to detect OTPIsADevice then replace with lookahead and lookbehind to find uppercase with a lowercase: (((?<!^)[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))
Note that | is or operator which allowed all the regex to be executed.
Regex: (?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}|(?<=[a-z])(?=\d)|(?<=\d)(?=[a-z])|(?<=[A-Z])(?=\d)|(?<=\d)(?=[A-Z])|(((?<!^)[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))
Demo
Update
Improvised a bit:
From: (?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}|(?<=[a-z])(?=\d)|(?<=\d)(?=[a-z])|(?<=[A-Z])(?=\d)|(?<=\d)(?=[A-Z])
into: (?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}|(?<=\p{L})\d which do the same thing.
(((?<!^)(?<!\p{P})[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))|(?<!^)(?=[[({&])|(?<=[)\]}!&}]) improvised from OP comment which is adding exception to some punctuation: (((?<!^)(?<!['([{])[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))|(?<!^)(?=[[({&])|(?<=[)\\]}!&}])
Final regex:
(?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}|(?<=\p{L})\d|(((?<!^)(?<!\p{P})[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))|(?<!^)(?=[[({&])|(?<=[)\]}!&}])
Demo
Aiming for simplicity rather than huge regex, I would recommend this code with small simple patterns (comments with explanation are in code):
string str = "ThisIsAnExampleTitleHELLO-WORLD2019T.E.S.T.(Test)\"Test\"'Test'[Test]";
// insert space when there is small letter followed by upercase letter
str = Regex.Replace(str, "(?<=[a-z])(?=[A-Z])", " ");
// insert space whenever there's digit followed by a ltter
str = Regex.Replace(str, #"(?<=\d)(?=[A-Za-z])", " ");
// insert space when there's letter followed by digit
str = Regex.Replace(str, #"(?<=[A-Za-z])(?=\d)", " ");
// insert space when there's one of characters ("'[ followed by letter or digit
str = Regex.Replace(str, #"(?=[(\[""'][a-zA-Z0-9])", " ");
// insert space when what preceeds is on of characters ])"'
str = Regex.Replace(str, #"(?<=[)\]""'])", " ");
You could reduce the requirements to shorten the steps of a regular expression using a different interpretation of them. For example, the first requirement would be the same as to say, preserve capital letters if they are not preceded by punctuation marks or capital letters.
The following regex works almost for all of the mentioned requirements and may be extended to include or exclude other situations:
(?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}
You have to use Replace() method and use $0 as substitution string.
See live demo here
.NET (See it in action):
string input = #"ThisIsAnExample.TitleHELLO-WORLD2019T.E.S.T.(Test)""Test""'Test'[Test]";
Regex regex = new Regex(#"(?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}", RegexOptions.Multiline);
Console.WriteLine(regex.Replace(input, #" $0"));
Related
I'm using Replace(#"[^a-zA-Z]+", "");
leave only letters, but I have a set of numbers or characters that I want to keep as well, ex: 122456 and 112466. But I'm having trouble leaving it only if it's this sequence:
ex input:
abc 1239 asm122456000
I want to:
abscasm122456
tried this: ([^a-zA-Z])+|(?!122456)
My answer doesn't applying Replace(), but achieves a similar result:
(?:[a-zA-Z]+|\d{6})
which captures the group (non-capturing group) with the alphabetic character(s) or a set of digits with 6 occurrences.
Regex 101 & Test Result
Join all the matching values into a single string.
using System.Linq;
Regex regex = new Regex("(?:[a-zA-Z]+|\\d{6})");
string input = "abc 1239 asm12245600";
string output = "";
var matches = regex.Matches(input);
if (matches.Count > 0)
output = String.Join("", matches.Select(x => x.Value));
Sample .NET Fiddle
Alternate way,
using .Split() and .All(),
string input = "abc 1239 asm122456000";
string output = string.Join("", input.Split().Where(x => !x.All(char.IsDigit)));
.NET Fiddle
It is very simple: you need to match and capture what you need to keep, and just match what you need to remove, and then utilize a backreference to the captured group value in the replacement pattern to put it back into the resulting string.
Here is the regex:
(122456|112466)|[^a-zA-Z]
See the regex demo. Details:
(122456|112466) - Capturing group with ID 1: either of the two alternatives
| - or
[^a-zA-Z] - a char other than an ASCII letter (use \P{L} if you need to match any char other than any Unicode letter).
Note the removed + quantifier as [^A-Za-z] also matches digits.
You need to use $1 in the replacement:
var result = Regex.Replace(text, #"(122456|112466)|[^a-zA-Z]", "$1");
I am trying to convert a Pascal Case string with numbers to a sentence:
OpenHouse2StartTimestamp = > Open House 2 Start Timestamp
I've been able to use regex to separate them without numbers, thanks to this answer, but how to do so when numbers are present is eluding me:
string sentence = Regex.Replace(label, "[a-z][A-Z]", m => m.Value[0] + " " + m.Value[1]);
How can I add numbers into the mix?
You can use
var sentence = Regex.Replace(label, #"(?<=[a-z])(?=[A-Z])|(?<=\d)(?=\D)|(?<=\D)(?=\d)", " ");
See the .NET regex demo. The regex matches:
(?<=[a-z])(?=[A-Z])| - a location between a lower- and an uppercase ASCII letters, or
(?<=\d)(?=\D)| - a location between a digit and a non-digit, or
(?<=\D)(?=\d) - a location between a non-digit and a digit.
Since all you need is inserting a space at the positions matched, you do not need a Match evaluator, just use a string replacement pattern.
Using the C# Regex.Split method, I would like to split strings that will always start with RepXYZ, Where the XYZ bit is a number that will always have either 3 or 4 characters.
Examples
"Rep1007$chkCheckBox"
"Rep127_Group_Text"
The results should be:
{"Rep1007","$chkCheckBox"}
{"Rep127","_Group_Text"}
So far I have tried (Rep)[\d]{3,4} and ((Rep)[\d]{3,4})+ but both of those are giving me unwanted results
Using Regex.Split often results in empty or unwanted items in the resulting array. Using (Rep)[\d]{3,4} in Regex.Split, will put Rep without the numbers into the resulting array. (Rep[\d]{3,4}) will put the Rep and the numbers into the result, but since the match is at the start, there will be an empty item in the array.
I suggest using Regex.Match here:
var match = Regex.Match(text, #"^(Rep\d+)(.*)$");
if (match.Success)
{
Console.WriteLine(match.Groups[1].Value);
Console.WriteLine(match.Groups[2].Value);
}
See the regex demo
Details:
^ - start of string
(Rep\d+) - capturing group 1: Rep and any one or more digits
(.*) - capturing group 2: any one or more chars other than a newline, as many as possible
$ - end of string.
A splitting approach is better implemented with a lookaround-based regex:
var results = Regex.Split(text, #"(?<=^Rep\d+)(?=[$_])");
See this regex demo.
(?<=^Rep\d+)(?=[$_]) splits a string at the location that is immediately preceded with Rep and one or more digits at the start of the string, and immediately followed with $ or _.
Try splitting on the regex pattern on either $ or _:
string input = "Rep127_Group_Text";
string[] parts = input.Split(new[] { '$', '_' }, 2);
foreach (string part in parts)
{
Console.WriteLine(part);
}
This prints:
Rep127
Group_Text
My task is to select first sentence from a text (I'm writing in C#). I suppose that the most appropriate way would be using regex but some troubles occurred. What regex pattern should I use to select the first sentence?
Several examples:
Input: "I am a lion and I want to be free. Do you see a lion when you look inside of me?" Expected result: "I am a lion and I want to be free."
Input: "I drink so much they call me Charlie 4.0 hands. Any text." Expected result: "I drink so much they call me Charlie 4.0 hands."
Input: "So take out your hands and throw the H.U. up. 'Now wave it around like you don't give a fake!'" Expected result: "So take out your hands and throw the H.U. up."
The third is really confusing me.
Since you aleready provided some assumptions:
sentences are divided by a whitespace
task is to select first sentence
You can use the following regex:
^.*?[.?!](?=\s+(?:$|\p{P}*\p{Lu}))
See RegexStorm demo
Regex breakdown:
^ - start of string (thus, only the first sentence will be matched)
.*? - any number of characters, as few as possible (use RegexOptions.Singleline to also match a newline with .)
[.?!] - a final punctuation symbol
(?=\s+(?:$|\p{P}*\p{Lu})) - a look-ahead making sure there is 1 or more whitespace symbols (\s+) right after before the end of string ($) or optional punctuation (\p{P}) and a capital letter (\p{Lu}).
UPDATE:
Since it turns out you can have single sentence input, and your sentences can start with any letter or digit, you can use
^.*?[.?!](?=\s+\p{P}*[\p{Lu}\p{N}]|\s*$)
See another demo
I came up with a regular expression that uses lots of negative look-aheads to exclude certain cases, e.g. a punctuation must not be followed by lowercase character, or a dot before a capital letter is not closing a sentence. This splits up all the text in their seperate sentences. If you are given a text, just take the first match.
[\s\S]*?(?![A-Z]+)(?:\.|\?|\!)(?!(?:\d|[A-Z]))(?! [a-z])/gm
Sentence separators should be searched with following scanner:
if it's sentence-finisher character (like [.!?])
it must be followed by space or allowed sequence of characters and then space:
like sequence of '.' for '.' (A sentence...)
...or sequence of '!' and/or '?' for '!' and '?' (Exclamation here!?)
then it must be followed by either:
capital character (ignore quotes, if any)
numeric
which must be followed by lowercase or another sentence-finister
dialog-starter character (Blah blah blah... - And what next, Elric?)
Tip: don't forget to add extra space character to input source string.
Upd:
Some wild pseudocode xD:
func sentence(inputString) {
finishers = ['.', '!', '?']
allowedSequences = ['.' => ['..'], '!' => ['!!', '?'], '?' => ['??', '!']]
input = inputString
result = ''
found = false
while input != '' {
finisherPos = min(pos(input, finishers))
if !finisherPos
return inputString
result += substr(input, 0, finisherPos + 1)
input = substr(input, finisherPos)
p = finisherPos
finisher = input[p]
p++
if input[p] != ' '
if match = testSequence(substr(input, p), allowedSequences[finisher]) {
result += match
found = true
break
} else {
continue
}
else {
p++
if input[p] in [A-Z] {
found = true
break
}
if input[p] in [0-9] {
p++
if input[p] in [a-z] or input[p] in finishers {
found = true
break
}
p--
}
if input[p] in ['-'] {
found = true;
break
}
}
}
if !found
return inputStr
return result
}
func testSequence(str, sequences) {
foreach (sequence: sequences)
if startsWith(str, sequence)
return sequence
return false
}
I have a long string composed of a number of different words.
I want to go through all of them, and if the word contains a special character or number (except '-'), or starts with a Capital letter, I want to delete it (the whole word not just that character). For all intents and purposes 'foreign' letters can count as special characters.
The obvious solution is to run a loop through each word (after splitting it) and then a loop through each character - but I'm hoping there's a faster way of doing it? Perhaps using Regex but I've almost no experience with it.
Thanks
ADDED:
(What I want for example:)
Input: "this Is an Example of 5 words in an input like-so from example.com"
Output: {this,an,of,words,in,an,input,like-so,from}
(What I've tried so far)
List<string> response = new List<string>();
string[] splitString = text.Split(' ');
foreach (string s in splitString)
{
bool add = true;
foreach (char c in s.ToCharArray())
{
if (!(c.Equals('-') || (Char.IsLetter(c) && Char.IsLower(c))))
{
add = false;
break;
}
if (add)
{
response.Add(s);
}
}
}
Edit 2:
For me a word should be a number of characters (a..z) seperated by a space. ,/./!/... at the end shouldn't count for the 'special character' condition (which is really mostly just to remove urls or the like)
So:
"I saw a dog. It was black!"
should result in
{saw,a,dog,was,black}
So you want to find all "words" that only contain characters a-z or -, for words that are separated by spaces?
A regex like this will find such words:
(?<!\S)[a-z-]+(?!\S)
To also allow for words that end with single punctuation, you could use:
(?<!\S)[a-z-]+(?=[,.!?:;]?(?!\S))
Example (ideone):
var re = #"(?<!\S)[a-z-]+(?=[,.!?:;]?(?!\S))";
var str = "this, Is an! Example of 5 words in an input like-so from example.com foo: bar?";
var m = Regex.Matches(str, re);
Console.WriteLine("Matched: ");
foreach (Match i in m)
Console.Write(i + " ");
Notice the punctuation in the string.
Output:
Matched:
this an of words in an input like-so from foo bar
How about this?
(?<=^|\s+)(?[a-z-]+)(?=$|\s+)
Edit: Meant (?<=^|\s+)(?<word>[a-z\-]+)(?=(?:\.|,|!|\.\.\.)?(?:$|\s+))
Rules:
Word can only be preceded by start of line or some number of whitespace characters
Word can only be followed by end of line or some number of whitespace characters (Edit supports words ending with periods, commas, exclamation points, and ellipses)
Word can only contain lower case (latin) letters and dashes
The named group containing each word is "word"
Have a look at Microsoft's How to: Search Strings Using Regular Expressions (C# Programming Guide) - it's about regexes in C#.
List<string> strings = new List<string>() {"asdf", "sdf-sd", "sdfsdf"};
for (int i = strings.Count-1; i > 0; i--)
{
if (strings[i].Contains("-"))
{
strings.Remove(strings[i]);
}
}
This could be a starting point. right now it just checks only for "." as a special char. This outputs : "this an of words in an like-so from"
string pattern = #"[A-Z]\w+|\w*[0-9]+\w*|\w*[\.]+\w*";
string line = "this Is an Example of 5 words in an in3put like-so from example.com";
System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex(pattern);
line = r.Replace(line,"");
You can do this in two ways, the white-list way and the black-list way. With a white-list you define the set of characters that you consider to be acceptable and with the black-list its the opposite.
Lets assume the white-list way and that you accept only characters a-z, A-Z and the - character. Additionally you have the rule that the first character of a word cannot be an upper case character.
With this you can do something like this:
string target = "This is a white-list example: (Foo, bar1)";
var matches = Regex.Matches(target, #"(?:\b)(?<Word>[a-z]{1}[a-zA-Z\-]*)(?:\b)");
string[] words = matches.Cast<Match>().Select(m => m.Value).ToArray();
Console.WriteLine(string.Join(", ", words));
Outputs:
// is, a, white-list, example
You can use look-aheads and look-behinds to do this. Here's a regex that matches your example:
(?<=\s|^)[a-z-]+(?=\s|$)
The explanation is: match one or more alphabetic characters (lowercase only, plus hyphen), as long as what comes before the characters is whitespace (or the start of the string), and as long as what comes after is whitespace or the end of the string.
All you need to do now is plug that into System.Text.RegularExpressions.Regex.Matches(input, regexString) to get your list of words.
Reference: http://www.mikesdotnetting.com/Article/46/CSharp-Regular-Expressions-Cheat-Sheet