I want to completely discard a match if it begins with the letter C.
This is an example text, each line is a separate example:
C4526913CA57248560A562492460C
A000008002A20839256662C
C370694CA102000979A68008192429291C
The regex I am using is
[cC]?([0-9*dD]){5,}[cC]
Match :
1: C4526913C
2: 562492460C
3: 20839256662C
4: C370694C
5: 68008192429291C
but I don't want to match the ones that start with C, and I have tried these
(?!^[cC])[cC]?([0-9*dD]){5,}[cC]
(?![cC].*[cC])([cC]?([0-9*dD]){5,}[cC])
Which adds a negative look ahead but instead it matches everything except the starting C instead of discarding the whole match. Like so:
C4526913C -> 4526913C
How can I achieve this with just regular expressions?
You can match what you don't want and capture in a group what you want to keep.
As there is a single character class in the group ([0-9*dD]){5,} you can omit the group and just repeat the character class.
Note that [0-9*dD] matches a digit 0-9 or * or d or D but only the digits are in the example data to match.
[cC][0-9*dD]{5,}[cC]|([0-9*dD]{5,}[cC])
Regex demo
For the example data (without D d and *) you could also use a lookbehind if that is supported:
(?<![cC0-9])[0-9]{5,}[cC]
Regex demo
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 am extracting a piece of string from a string (link):
https://arteptweb-vh.akamaihd.net/i/am/ptweb/100000/100000/100095-000-A_0_VO-STE%5BANG%5D_AMM-PTWEB_XQ.1V7rLEYkPH.smil/master.m3u8
The desired output should be 100000/100000/100095-000-A_
I am using the Regex ^.*?(/[i,na,fm,d]([,/]?)(/am/ptweb/|.+=.+,))([^_]*).*?$ in Golang flavor and I can get only the group 4 with the folowing output 100000/100000/100095-000-A
However I want the underscore after A.
Bit stuck on this, any help on this is appreciated.
You can use
(/(i|na|fm|d)(/am/ptweb/|.+=.+,))([^_]*_?)
See the regex demo.
Details:
(/(i|na|fm|d)(/am/ptweb/|.+=.+,)) - Group 1:
/ - a / char
(i|na|fm|d) - Group 2: i, na, fm or d
(/am/ptweb/|.+=.+,) - Group 3: /amp/ptweb/ or one or more chars as many as possible (other than line break chars), =, one or more chars as many as possible (other than line break chars) and a , char
([^_]*_?) - Group 4: zero or more chars other than _ and then an optional _.
You can match the underscore after the A like:
^.*?(/(?:[id]|na|fm)([,/]?)(/am/ptweb/|.+=.+,))([^_]*_).*$
See a regex demo
A few notes about the pattern that you tried:
This notation is a character class [i,na,fm,d] which should be a grouping (?:[id]|na|fm)
In this group ([,/]?) you optionally capture either , or / so in theory it could match a string that has /i//am/ptweb/
The last part .*?$ does not have to be non greedy as it is the last part of the pattern
This part [^_]* can also match spaces and newlines
I want to expect some characters only if a prior regex matched. If not, no characters (empty string) is expected.
For instance, if after the first four characters appears a string out of the group (A10, B32, C56, D65) (kind of enumeration) then a "_" followed by a 3-digit number like 123 is expected. If no element of the mentioned group appears, no other string is expected.
My first attempt was this but the ELSE branch does not work:
^XXX_(?<DT>A12|B43|D14)(?(DT)(_\d{1,3})|)\.ZZZ$
XXX_A12_123.ZZZ --> match
XXX_A11.ZZZ --> match
XXX_A12_abc.ZZZ --> no match
XXX_A23_123.ZZZ --> no match
These are examples of filenames. If the filename contains a string of the mentioned group like A12 or C56, then I expect that this element if followed by an underscore followed by 1 to 3 digits. If the filename does not contain a string of that group (no character or a character sequence different from the strings in the group) then I don't want to see the underscore followed by 1 to 3 digits.
For instance, I could extend the regex to
^XXX_(?<DT>A12|B43|D14)_\d{5}(?(DT)(_\d{1,3})|)_someMoreChars\.ZZZ$
...and then I want these filenames to be valid:
XXX_A12_12345_123_wellDone.ZZZ
XXX_Q21_00000_wellDone.ZZZ
XXX_Q21_00000_456_wellDone.ZZZ
...but this is invalid:
XXX_A12_12345_wellDone.ZZZ
How can I make the ELSE branch of the conditional statement work?
In the end I intend to have two groups like
Group A: (A11, B32, D76, R33)
Group B: (A23, C56, H78, T99)
If an element of group A occurs in the filename then I expect to find _\d{1,3} in the filename.
If an element of group B occurs ion the filename then the _\d{1,3} shall be optional (it may or may not occur in the filename).
I ended up in this regex:
^XXX_(?:(?A12|B43|D14))?(?(DT)(_\d{5}_\d{1,3})|(?!(?&DT))(?!.*_\d{3}(?!\d))).*\.ZZZ$
^XXX_(?:(?<DT>A12|B43|D14))?_\d{5}(?(DT)(_\d{1,3})|(?!(?&DT))(?!.*_\d{3}(?!\d))).+\.ZZZ$
Since I have to use this regex in the OpenApi #Pattern annotation I have the problem that I get the error:
Conditionals are not supported in this regex dialect.
As #The fourth bird suggested alternation seems to do the trick:
XXX_((((A12|B43|D14)_\d{5}_\d{1,3}))|((?:(A10|B10|C20)((?:_\d{5}_\d{3})|(?:_\d{3}))))).*\.ZZZ$
The else branch is the part after the |, but if you also want to match the 2nd example, the if clause would not work as you have already matched one of A12|B43|D14
The named capture group is not optional, so the if clause will always be true.
What you can do instead is use an alternation to match either the numeration part followed by an underscore and 3 digits, or match an uppercase char and 2 digits.
^XXX_(?:(?<DT>A12|B43|D14)_\d{1,3}|[A-Z]\d{2})\.ZZZ$
Regex demo
If you want to make use of the if/else clause, you can make the named capture group optional, and then check if group 1 exists.
^XXX_(?<DT>A12|B43|D14)?(?(DT)_\d{1,3}|[A-Z]\d{2})\.ZZZ$
Regex demo
For the updated question:
^XXX_(?<DT>A12|B43|D14)?(?(DT)(?:_\d{5})?_\d{3}(?!\d)|(?!A12|B43|D14|[A-Z]\d{2}_\d{3}(?!\d))).*\.ZZZ$
The pattern matches:
^ Start of string
XXX_ Match literally
(?<DT>A12|B43|D14)?
(?(DT) If we have group DT
(?:_\d{5})? Optionally match _ and 5 digits
_\d{3}(?!\d) Match _ and 3 digits
| Or
(?! Negative lookahead, assert not to the right
A12|B43|D14| Match one of the alternatives, or
[A-Z]\d{2}_\d{3}(?!\d) Match 1 char A-Z, 2 digits _ 3 digits not followed by a digit
) Close lookahead
) Close if clause
.* Match the rest of the line
\.ZZZ Match . and ZZZ
$ End of string
Regex demo
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
Intro
I have a string containing diagnosis codes (ICD-10), not separated by any character. I would like to extract all valid diagnosis codes. Valid diagnosis codes are of the form
[Letter][between 2 and 4 numbers][optional letter that is not the next match starting letter]
The regex for this pattern is (I believe)
\w\d{2,4}\w?
Example
Here is an example
mystring='F328AG560F33'
In this example there are three codes:
'F328A' 'G560' 'F33'
I would like to extract these codes with a function like str_extract_all in R (preferably but not exclusively)
My solution so far
So far, I managed to come up with an expression like:
str_extract_all(mystring,pattern='\\w\\d{2,4}\\w?(?!(\\w\\d{2,4}\\w?))')
However when applied to the example above it returns
"F328" "G560F"
Basically it misses the letter A in the first code, and misses altogether the last code "F33" by mistakenly assigning F to the preceding code.
Question
What am I doing wrong? I only want to extract values that end with a letter that is not the start of the next match, and if it is, the match should not include the letter.
Application
This question is of great relevance for example when mining patient Electronic Health Records that have not been validated.
You have a letter, two-to-four numbers then an optional letter. That optional letter, if it's there, will only ever be followed by another letter; or, put another way, never followed by a number. You can write a negative lookahead to capture this:
\w\d{2,4}(?:\w(?!\d))?
This at least works with PCRE. I don't know about how R will handle it.
Your matches are overlapping. In this case, you might use str_match_all that allows easy access to capturing groups and use a pattern with a positive lookahead containing a capturing group inside:
(?i)(?=([A-Z]\d{2,4}(?:[A-Z](?!\d{2,4}))?))
See the regex demo
Details
(?= - a positive lookahead start (it will be run at every location before each char and at the end of the string
( - Group 1 start
[A-Z] - a letter (if you use a case insensitive modifier (?i), it will be case insensitive)
\d{2,4} - 2 to 4 digit
(?: - an optional non-capturing group start:
[A-Z] - a letter
(?!\d{2,4}) - not followed with 2 to 4 digits
)? - the optional non-capturing group end
) - Group 1 end
) - Lookahead end.
R demo:
> library(stringr)
> res <- str_match_all("F328AG560F33", "(?i)(?=([A-Z]\\d{2,4}(?:[A-Z](?!\\d{2,4}))?))")
> res[[1]][,2]
[1] "F328A" "G560" "F33"