is it possible to solve this with just one regex? - regex

I would like to know if there is a regular expression that given for example this input:
lkjs kjsfjk ijsfj á 13total wer6klje additional lñk jshv kjsdfjk dj d 22total kejk jksfljkakvhjr j 3total fkljbher jr6 hrew7 hwr 41total sfdkj additional iuwefjkwf7 7erfh sf 5total klj kj kjsef87 jhwfe7 89 jhf
could output these 3 matches, which are numbers followed by total, that do not contain the word additional after (and before finding the next number):
22
3
5
So, for example I didn't match 13 because
13total wer6klje additional lñk jshv kjsdfjk dj d 22total
contains the word additional
And I didn't match 41 because
41total sfdkj additional iuwefjkwf7 7erfh sf 5total
contains the word additional
let me explain the input structure used in the example:
randomText 13total randomText aditional randomText
22total randomText
3total randomText
41total randomText aditional randomText
5total randomText
So basically the input is something like:
randomText X_total randomText_that_contains_or_not_'additional'
X_total randomText_that_contains_or_not_'additional'
....
X_total randomText_that_contains_or_not_'additional'
I know how to solve the problem using some additional code (using several patterns and matches, if-else structures...) but the system I'm working with, cannot make use of those. It just can be fed up with one regular expression (it's a complicated system, not easy to modify).
So, for example, with the regular expression [0-9]+(?=total) I would get this matches: 13, 22, 3, 41, 5
but as I said I just need 22, 3, 5
Can anybody build a more complex regular expression that matches those 3 numbers?
Thanks!

Of course it is possible (given that your regex flavour supports lookahead assertions)
\d+(?=total(?!\D*additional))
See it here on regex101
\d+ matches one ore more digits
(?=total(?!\D*additional)) nested lookaround assertions. Digits has to be followed by "total" not followed by additional (with only non digits inbetween)
A more advanced example based on Bergis comment:
\d+(?=total(?!(?:.(?!\d+total))*additional))
See it on regex101
Here I searching for additional as long as I not find \d+total

You can use (the total will always be preceded by a digit, right?)
\d+(?=total(?!(?:\D|\d(?!total))*additional))
Explanation
The idea is to forbid any additional before the next <digit>total:
\d+ # digits
(?=total # followed by total
(?! # not followed by...
(?:
\D++ # not a digit (possessive quantifier)
| # OR
\d(?!total) # a digit, but not followed by total
)*+ # any number of times
additional
)
)
The negative look ahead will fail the regex if it finds one, and we're sure not to pass over a <digit>total thanks to (?:\D|\d(?!total)).
See demo here.

Related

Regex to get any numbers after the occurrence of a string in a line

Hi guys im trying to get the the substring as well as the corresponding number from this string
text = "Milk for human consumption may be taken only from cattle from 80 hours after the last treatment."
I want to select the word milk and the corresponding number 80 from this sentence. This is part of a larger file and i want a generic solution to get the word milk in a line and then the first number that occurs after this word anywhere in that line.
(Milk+)\d
This is what i came up with thinking that i can make a group milk and then check for digits but im stumped how to start a search for numbers anywhere on line and not just immediately after the word milk. Also is there any way to make the search case insensitive?
Edit: im looking to get both the word and the number if possible eg: "milk" "80" and using python
/(?<!\p{L})([Mm]ilk)(?!p{L})\D*(\d+)/
This matches the following strings, with the match and the contents of the two capture groups noted.
"The Milk99" # "Milk99" 1:"Milk" 2:"99"
"The milk99 is white" # "milk99" 1:"milk" 2:"99"
"The 8 milk is 99" # "milk is 99" 1:"milk" 2:"99"
"The 8milk is 45 or 73" # "milk is 45" 1:"milk" 2:"45"
The following strings are not matched.
"The Milk is white"
"The OJ is 99"
"The milkman is 37"
"Buttermilk is 99"
"MILK is 99"
This regular expression could be made self-documenting by writing it in free-spacing mode:
/
(?<!\p{L}) # the following match is not preceded by a Unicode letter
([Mm]ilk) # match 'M' or 'm' followed by 'ilk' in capture group 2
(?!p{L}) # the preceding match is not followed by a Unicode letter
\D* # match zero or more characters other than digits
(\d+) # match one or more digits in capture group 2
/x # free-spacing regex definition mode
\D* could be replaced with .*?, ? making the match non-greedy. If the greedy variant were used (.*), the second capture group for "The 8milk is 45 or 73" would contain "3".
To match "MILK is 99", change ([Mm]ilk) to (?i)(milk).
This seems to work in java (I overlooked that the questioner wanted python or the question was later edited) like you want to:
String example =
"Test 40\n" +
"Test Test milk for human consumption may be taken only from cattle from hours after the last treatment." +
"\nTest Milk for human consumption may be taken only from cattle from 80 hours after the last treatment." +
"\nTest miLk for human consumption may be taken only from cattle from 80 hours after the last treatment.";
Matcher m = Pattern.compile("((?i)(milk).*?(\\d+).*\n?)+").matcher(example);
m.find();
System.out.print(m.group(2) + m.group(3));
Look at how it tests whether the word "milk" appears in a case insensitive manner anywhere before a number in the exact same line and only prints these both. It also prints only the first found occurence (making it find all occurencies is also possible pretty easily just by a little modifications of the given code).
I hope the way it extracts these both things from a matching pattern is in the sense of your task.
You should try this one
(Milk).*?(\d+)
Based on your language, you can also specify a case-insensitive search. Example in JS: /(Milk).*?(\d+)/i, the final i makes the search case insensitive.
Note the *?, the most important part ! This is a lazy iteration. In other words, it reads any char, but as soon as it can stop and process the next instruction successfully then it does. Here, as soon as you can read a digit, you read it. A simple * would have returned the last number from this line after Milk instead

How to create a matching regex pattern for "greater than 10-000-000 and lower than 150-000-000"?

I'm trying to make
09-546-943
fail in the below regex pattern.
​^[0-9]{2,3}[- ]{0,1}[0-9]{3}[- ]{0,1}[0-9]{3}$
Passing criteria is
greater than 10-000-000 or 010-000-000 and
less than 150-000-000
The tried example "09-546-943" passes. This should be a fail.
Any idea how to create a regex that makes this example a fail instead of a pass?
You may use
^(?:(?:0?[1-9][0-9]|1[0-4][0-9])-[0-9]{3}-[0-9]{3}|150-000-000)$
See the regex demo.
The pattern is partially generated with this online number range regex generator, I set the min number to 10 and max to 150, then merged the branches that match 1-8 and 9 (the tool does a bad job here), added 0? to the two digit numbers to match an optional leading 0 and -[0-9]{3}-[0-9]{3} for 10-149 part and -000-000 for 150.
See the regex graph:
Details
^ - start of string
(?: - start of a container non-capturing group making the anchors apply to both alternatives:
(?:0?[1-9][0-9]|1[0-4][0-9]) - an optional 0 and then a number from 10 to 99 or 1 followed with a digit from 0 to 4 and then any digit (100 to 149)
-[0-9]{3}-[0-9]{3} - a hyphen and three digits repeated twice (=(?:-[0-9]{3}){2})
| - or
150-000-000 - a 150-000-000 value
) - end of the non-capturing group
$ - end of string.
This expression or maybe a slightly modified version of which might work:
^[1][0-4][0-9]-[0-9]{3}-[0-9]{3}$|^[1][0]-[0-9]{3}-[0-9]{2}[1-9]$
It would also fail 10-000-000 and 150-000-000.
In this demo, the expression is explained, if you might be interested.
This pattern:
((0?[1-9])|(1[0-4]))[0-9]-[0-9]{3}-[0-9]{3}
matches the range from (0)10-000-000 to 149-999-999 inclusive. To keep the regex simple, you may need to handle the extremes ((0)10-000-000 and 150-000-000) separately - depending on your need of them to be included or excluded.
Test here.
This regex:
((0?[1-9])|(1[0-4]))[0-9][- ]?[0-9]{3}[- ]?[0-9]{3}
accepts (space) or nothing instead of -.
Test here.

Python Regular Expression: No space in between

I have the following string:
"......(some chars) aaa bbb ###8/13/2018 ......(some chars)"
The ### in the string represent some random characters. ###'s length is unknown and it could be None (just "aaa bbb 8/13/2018").
My goal is to find the date from the string (8/13/2018) and the starting index of ###.
I currently used the following code:
m = re.search(r'\s.*?([0-9]{1,}/[0-9]{1,}/[0-9]{2,})', str)
m.groups()[0] ## The date
m.start() ## index of ###
But the regex is matching bbb ###8/13/2018 instead of ###8/13/2018
I also tried change the regex to:
r'\s(?!\s).*?[0-9]{1,}/[0-9]{1,}/[0-9]{2,}'
r'\s(?!\s)*?[0-9]{1,}/[0-9]{1,}/[0-9]{2,}'
But neither of them works.
I will be appreciated for any help or comments. Thank you.
I tend to believe you are looking for:
#*(?:\d{1,2}/){2}\d{2,4} or even \S*(?:\d{1,2}/){2}\d{2,4}
This is simply saying:
\S* start with 0 or more non-space charaters.
(?:\d{1,2}/){2} find two groups of \d{1,2}/ but do not capture them. ie not capturing: (?:..).this will match the month and date part 8/13/. \d{1,2} means atleast one digit and atmost two digits
\d{2,4} match the year .Atleast 2 digits and atmost 4 digits
Using a part of your regex, I think you mean something like this
r'\S*([0-9]+/[0-9]+/[0-9]{2,})'
https://regex101.com/r/dxF4sT/1
To find the starting index, it would be where the match was found.
Note that \S will find all consecutive non-whitespace.
You can change this to other things like [#a-zA-Z] etc..., just add it to the class.

Trying to create a regex that allowes following format yyyy[: -][VW]Week number

My regex currently looks like this
\b(19|20)\d{2}\b[- :][VW][0-5]{1}(?(?=[5])[0-2]{1}|[0-9]{1})
It doesn't quite do what I want as I'm trying to get this part
(?(?=[5])[0-2]{1}|[0-9]{1})
to say "If the previous number was 5 then you may only choose between 0-2, and if it's another number 0-4 then choosing between 0-9 is allowed
Currently it allowes 00-59 with an exclusion of 05,15,25,35 etc.
Essentially I want it to look like this for example 2016-W25.
You need to replace [5] with a positive lookbehind (?<=5) in order to check a char to the left of the current location:
\b(19|20)\d{2}[- :][VW][0-5](?(?=(?<=5))[0-2]|[0-9])
^^^^^
See the regex demo
Also, you may get rid of the conditional pattern at all using a mere alternation group:
\b(19|20)\d{2}[- :][VW](?:[0-4][0-9]|5[0-2])
^^^^^^^^^^^^^^^^^^^^^
See this regex demo
The (?:[0-4][0-9]|5[0-2]) matches either a digit from 0 to 4 and then any digit (see [0-4][0-9]), or (see |) a 5 followed with 0, 1 or 2 (see 5[0-2]).
NOTE: Since the number of weeks can amount to 53, the [0-2] at the end might be replaced with [0-3] to also match 53 values.

Regex failing to match number and dash with letter (or space and letter)

In the tester this works ... but not in PostgreSQL.
My data is like this -- usually a series of letters, followed by 2 numbers and a POSSIBLE '-' or 'space' with only ONE letter following. I am trying to isolate the 2 numbers and the Possible '-" or 'space' AND the ONE letter with my regex:
For ex:
AJ 50-R Busboys ## should return 50-R
APPLES 30 F ## should return 30 F
FOOBAR 30 Apple ## should return 30
Regex's (that have worked in the tester, but not in PostgreSQL) that I've tried:
substring(REF from '([0-9]+)-?([:space:])?([A-Za-z])?')
&
substring(REF from '([0-9]+)-?([A-Za-z])?')
So far everything tests out in the tester...but not the PostgreSQL. I just keep getting the numbers returns -- AND NOTHING AFTER IT.
What I am getting now(for ex):
AJ 50-R Busboys ## returns as "50" NOT as "50-R"
Your looking for: substring(REF from '([0-9]+(-| )([A-Za-z]\y)?)')
In SQLFiddle. Your primary problem is that substring returns the first or outermost matching group (ie., pattern surrounded with ()), which is why you get 50 for your '50-R'. If you were to surround the entire pattern with (), this would give you '50-R'. However, the pattern you have fails to return what you want on the other strings, even after accounting for this issue, so I had to modify the entire regex.
This matches your description and examples.
Your description is slightly ambiguous. Leading letters are followed by a space and then two digits in your examples, as opposed to your description.
SELECT t, substring(t, '^[[:alpha:] ]+(\d\d(:?[\s-]?[[:alpha:]]\M)?)')
FROM (
VALUES
('AJ 50-R Busboys') -- should return: 50-R
,('APPLES 30 F') -- should return: 30 F
,('FOOBAR 30 Apple') -- should return: 30
,('FOOBAR 30x Apple') -- should return: 30x
,('sadfgag30 D 66 X foo') -- should return: 30 D - not: 66 X
) r(t);
->SQLfiddle
Explanation
^ .. start of string (last row could fail without anchoring to start and global flag 'g'). Also: faster.
[[:alpha:] ]+ .. one or more letters or spaces (like in your examples).
( .. capturing parenthesis
\d\d .. two digits
(:? .. non-capturing parenthesis
[\s-]? .. '-' or 'white space' (character class), 0 or 1 times
[[:alpha:]] .. 1 letter
\M .. followed by end of word (can be end of string, too)
)? .. the pattern in non-capturing parentheses 0 or 1 times
Letters as defined by the character class alpha according to the current locale! The poor man's substitute [a-zA-Z] only works for basic ASCII letters and fails for anything more. Consider this simple demo:
SELECT substring('oö','[[:alpha:]]*')
,substring('oö','[a-zA-Z]*');
More about character classes in Postgres regular expressions in the manual.
It's because of the parentheses.
I've looked everywhere in the documentation and found an interesting sentence on this page:
[...] if the pattern contains any parentheses, the portion of the text that matched the first parenthesized subexpression (the one whose left parenthesis comes first) is returned.
I took your first expression:
([0-9]+)-?([:space:])?([A-Za-z])?
and wrapped it in parentheses:
(([0-9]+)-?([:space:])?([A-Za-z])?)
and it works fine (see SQLFiddle).
Update:
Also, because you're looking for - or space, you could rewrite your middle expression to [-|\s]? (thanks Matthew for pointing that out), which leads to the following possible REGEX:
(([0-9]+)[-|\s]?([A-Za-z])?)
(SQLFiddle)
Update 2:
While my answer provides the explanation as to why the result represented a partial match of your expression, the expression I presented above fails your third test case.
You should use the regex provided by Matthew in his answer.