I have a dataset with repeating pattern in the middle:
YM10a15b5c27
and
YM1b5c17
How can I get what is between "YM" and the last two numbers?
I'm using this but is getting one number in the end and should not.
/([A-Z]+)([0-9a-z]+)([0-9]+)/
Capture exactly two characters in the last group:
/([A-Z]+)([0-9a-z]+)([0-9]{2})/
You should use:
/^(?:([a-z]+))([0-9a-z]+)(?=\1)/
^ matches the start of the sentence. This is really important, because if your code is aaaa1234aaaa, then without the ^, it would also match the aaaa of the end.
(?:([a-z]+)) is a non-capturing group which takes any letter from 'a' to 'z' as group 1
(?=\1) tells the regex to match the text as long as it is followed by the same code at the starting.
All you have to do is extract the code by group(2)
An example is shown here.
Solution
If you want to match these strings as whole words, use \b(([a-z])\2)([0-9a-z]+)(\1)\b. If you need to match them as separate strings, use ^(([a-z])\2)([0-9a-z]+)(\1)$.
Explanation
\b - a word boundary (or if ^ is used, start of string)
(([a-z])\2) - Group 1: any lowercase ASCII letter, exactly two occurrences (aa, bb, etc.)
([0-9a-z]+) - Group 3: 1 or more digits or lowercase ASCII letters
(\1) - Group 4: the same text as stored in Group 1
\b - a word boundary (or if $ is used, end of string).
Related
I have followings String:
test_abc123_firstrow
test_abc1564_secondrow
test_abc123_abc234_thirdrow
test_abc1663_fourthrow
test_abc193_abc123_fifthrow
I want to get the abc + following number of each row.
But just the first one if it has more than one.
My current pattern looks like this: ([aA][bB][cC]\w\d+[a-z]*)
But this doesn't involve the first one only.
If somebody could help how I can implement that, that would be great.
You can use
^.*?([aA][bB][cC]\d+[a-z]*)
Note the removed \w, it matches letters, digits and underscores, so it looks redundant in your pattern.
The ^.*? added at the start matches the
^ - start of string
.*? - any zero or more chars other than line break chars as few as possible
([aA][bB][cC]\d+[a-z]*) - Capturing group 1: a or A, b or B, c or C, then one or more digits and then zero or more lowercase ASCII letters.
Use the following regex:
^.*?([aA][bB][cC]\d+)
Use ^ to begin at the start of the input
.*? matches zero or more characters (except line breaks) as few times as possible (lazy approach)
The rest is then captured in the capturing group as expected.
Demo
I want to extract [games, games, things, things] from
the following array.
Today_games
Today_games_freq
Today_things
Today_things_freq
I have tried Today_(\w+)(?=_freq)?
Which will give me the extra "freq"
And some other combinations, but I couldn't figure out how to get just after the first hyphen.
You can use
Today_(\w+?)(?:_freq)?$
See the regex demo. This matches Today_, then captures any one or more word chars (as few as possible) into Group 1 (with (\w+?)), and then (?:_freq)?$ matches an optional occurrence of a _freq substring and asserts the position at the end of string.
Or,
Today_([^\W_]+)
See this regex demo.
Here, Today_ is matched and the ([^\W_]+) pattern captures one or more alphanumeric chars into Group 1 (same as \w+ with _ subtracted from \w).
there are 4 strings as shown below
ABC_FIXED_20220720_VALUEABC.csv
ABC_FIXED_20220720_VALUEABCQUERY_answer.csv
ABC_FIXED_20220720_VALUEDEF.csv
ABC_FIXED_20220720_VALUEDEFQUERY_answer.csv
Two strings are considered as matched based on a matching substring value (VALUEABC, VALUEDEF in the above shown strings). Thus I am looking to match first 2 (having VALUEABC) and then next 2 (having VALUEDEF). The matched strings are identified based on the same value returned for one regex group.
What I tried so far
ABC.*[0-9]{8}_(.*[^QUERY_answer])(?:QUERY_answer)?.csv
This returns regex group-1 (from (.*[^QUERY_answer])) value "VALUEABC" for first 2 strings and "VALUEDEF" for next 2 strings and thus desired matching achieved.
But the problem with above regex is that as soon as the value ends with any of the characters of "QUERY_answer", the regex doesn't match any value for the grouping. For instance, the below 2 strings doesn't match at all as the VALUESTU ends with "U" here :
ABC_FIXED_20220720_VALUESTU.csv
ABC_FIXED_20220720_VALUESTUQUERY_answer.csv
I tried to use Negative Lookahead:
ABC.*[0-9]{8}_(.*(?!QUERY_answer))(?:QUERY_answer)?.csv
but in this case the grouping-1 value is returned as "VALUESTU" for first string and "VALUESTUQUERY_answer" for second string, thus effectively making the 2 strings unmatched.
Any way to achieve the desired matching?
With your shown samples please try following regex.
^ABC_[^_]*_[0-9]+_(.*?)(?:QUERY_answer)?\.csv$
OR to match exact 8 digits try:
^ABC_[^_]*_[0-9]{8}_(.*?)(?:QUERY_answer)?\.csv$
Here is the online demo for above regex.
Explanation: Adding detailed explanation for above regex.
^ABC_[^_]*_ ##Matching from starting of value ABC followed by _ till next occurrence of _.
[0-9]+_ ##Matching continuous occurrences of digits followed by _ here.
(.*?) ##Creating one and only capturing group using lazy match which is opposite of greedy match.
(?:QUERY_answer)? ##In a non-capturing group matching QUERY_answer and keeping it optional.
\.csv$ ##Matching dot literal csv at the end of the value.
You need
ABC.*[0-9]{8}_(.*?)(?:QUERY_answer)?\.csv
See the regex demo.
Note
.*[^QUERY_answer] matches any zero or more chars other than line break chars as many as possible, and then any one char other than Q, U, E, etc., i.e. any char in the negated character class. This is replaced with .*?, to match any zero or more chars other than line break chars as few as possible.
(?:QUERY_answer)? - the group is made non-capturing to reduce grouping complexity.
\.csv - the . is escaped to match a literal dot.
I have patterns like
FQC19515_TCELL001_20190319_165944.pdf
FQC19515_TBNK001_20190319_165944.pdf
I can match word TCELL and TBNK with this RegEX
^(\D+)-(\d+)-(\d+)([A-Z1-9]+)?.*
But if I have patterns like
FLW194640_T20NK022_20190323_131348.pdf
FLW194228_C1920_SOME_DEBRIS_REMOVED.pdf
the above regex returns
T2 and C192 instead of T20NK and C1920 respectively
Is there a general regex that matches Nzeros out side of these word boundaries?
Let's consider all 4 examples of your input:
FQC19515_TCELL001_20190319_165944.pdf
FQC19515_TBNK001_20190319_165944.pdf
FLW194640_T20NK022_20190323_131348.pdf
FLW194228_C1920_SOME_DEBRIS_REMOVED.pdf
The first group, between start of line and the first "_" (e.g. FQC19515 in row 1)
consists of:
a non-empty sequence of letters,
a non-empty sequence of digits.
So the regex matching it, including the start of line anchor and a capturing group is:
^([A-Z]+\d+)
You used \D instead of [A-Z] but I think that [A-Z] is
more specific, as it matches only letters an not e.g. "_".
The next source char is _, so the regex can also include _.
A now the more diificult part: The second group to be captured has
actually 2 variants:
a sequence of letters and a sequence of digits (after that there is
a "_"),
a sequence of letters, a sequence of digits and another sequence of
letters (after that there are digits that you want to omit).
So the most intuitive way is to define 2 alternatives, each with
a respective positive lookahead:
alternative 1: [A-Z]+\d+(?=_),
alternative 2: [A-Z]+\d+[A-Z]+(?=\d).
But there is a bit shorter way. Notice that both alternatives start
from [A-Z]+\d+.
So we can put this fragment at the first place and only the rest
include as a non-capturing group ((?:...)), with 2 alternatives.
All the above should be surrounded with a capturing group:
([A-Z]+\d+(?:(?=_)|[A-Z]+(?=\d)))
So the whole regex can be:
^([A-Z]+\d+)_([A-Z]+\d+(?:(?=_)|[A-Z]+(?=\d)))
with m option ("^" matches also the start of each line).
For a working example see https://regex101.com/r/GDdt10/1
Your regex: ^(\D+)-(\d+) is wrong as after a sequence of non-digits
(\D+) you specified a minus which doesn't occur in your source.
Also the second minus does not correspond to your input.
Edit
To match all your strings, I modified slightly the previous regex.
The changes are limited to the matching group No 2 (after _):
Alternative No 1: [A-Z]{2,}+(?=\d) - two or more letters, after them
there is a digit, to be omitted. It will match TCELL and TBNK.
Alternative No 2: [A-Z]+\d+(?:(?=_)|[A-Z]+(?=\d)) - the previous
content of this group. It will match two remaining cases.
So the whole regex is:
^([A-Z]+\d+)_([A-Z]{2,}+(?=\d)|[A-Z]+\d+(?:(?=_)|[A-Z]+(?=\d)))
For a working example see https://regex101.com/r/GDdt10/2
As far as I understand, you could use:
^[A-Z]+\d+_\K[A-Z0-9]{5}
Explanation:
^ # beginning of line
[A-Z]+ # 1 or more capitals
\d+_ # 1 or more digit and 1 underscore
\K # forget all we have seen until this position
[A-Z0-9]{5} # 5 capitals or digits
Demo
I'd like to use Regex to determine whether the characters after the first are all numbers.
For example:
A123 would be valid as after A there are only numbers
A12B would be invalid as, after the first character, there is another letter
I essentially want to ignore the first character
I have so far this:
(?<=A)\w*(?=)
but this makes A12B or A1B2C valid, I only want numbers after A.
You could match not a digit \D, followed by matching 1+ times a digit. If that is the whole string, you could use anchors asserting the start ^ and the $ end of the string.
^\D\d+$
That will match:
^ Start of the string
\D Match not a digit
\d+ Match 1+ digits making sure there are digits
$ End of the string
Regex demo
The best solution I can think of is:
^.\d*$
^ - Start of the line
. - Any character (except line terminators)
\d*
\d- a number
* - repeated any number of times (including 0 times. If you want it to be at least 1, change it to +).
$ - End of the line
let regex = /^.\d*$/;
let testStrings = ['A123', 'A12B'];
testStrings.forEach(str => {
console.log(`${str} is ${regex.test(str) ? 'valid' : 'invalid'}`);
});
Your attempt is very complicated, especially given how simple is your goal.
Succeeding at regexes is all about simplicity.
The first character can be anything, so just go with ..
The next ones are all digits, so you want \d.
You'll star it to specify restriction-less repetition, or use + if you want at least one.
Finally, you need to anchor your regex at the beginning and at the end, else it would match stuff like A123XXXXX or XXXXA123.
Note that most implementations of match will already anchor the pattern at the end, so you can omit the caret at the beginning.
Final regex:
^.\d*$
Maybe
(?<=.{1,1})([0-9]+)(?=\s)
(?<=.{1,1}) - has exactly one character before
([0-9]+) - at least one digit
(?=\s) - has a whitespace after
Add ^ at the beginning - to specify beginning of line
Replace (?=\s) with $ for end of line
^[a-zA-Z][0-9]{3}$
^ - "starting with" (Here it is starting with any letter). Read it as ^[a-zA-Z]
[a-z] - any small letters and A-Z any capital letters (you may change if required.)
[0-9] - any numbers
{3} - describes how many numbers you want to check. You have to read it as [0-9]{3}
$ - End of the statement. (Means, in this case it will end up with 3 numbers)
Here you can play around - https://regex101.com/r/mqUHvP/5