I'm new here, so please don't scold me for misspellings etc.
What I need to do is to rename a bunch of files with a date in different formats at the beginning of their names, like:
05.07.2020-abc.pdf
2020.07.05-pqr.pdf
Instead of writing a different expression for each formatting, eg.
^(\d{2})\.(\d{2}).(\d{4})(.+) => $3-$2-$1$4
Example
02.11.2022-abc.pdf => 2022-11-02-abc.pdf
I'd like to do it in one fell swoop using the OR operator "|" but I have no idea how to formulate the groupings etc. Can one have nested groupings in regex?
Any ideas? Thank in advance!
#The fourth bird:
No (.+) needed. You're right, I condensed my actual expression and could have taken it out.
The different date 'formats' I mean are dd.mm.yyyy and yyyy.mm.dd respectively, and I need to convert both to yyyy-mn-dd
So,if the format is dd.mm.yyyy I have to flip the string, so to say, else I just need to replace the dots by hyphens.
The OS is Android, and for this operation I use Solid Explorer multi search & replace using regex.
I hope I made myself clear this time around ;-)
I need to find some specific characters in a cell and replace them with other characters.
So far I can do that by using :
=SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A1,"★","•",0),"<b>","",0),"</b>","",0),"✔ ","",0)
However, this formula will become very long if I need to replace a lot of characters. Is there any way to reduce the duplicate parts, especially when I need to replace some characters with only the other one. Ex: Replace , , ✔ with "" as example above.
Demo sheet: https://docs.google.com/spreadsheets/d/1wX9mEykCMjeotTRTg_jSMcm9Mm7WM0kPTetRwGLzaYU/edit#gid=0
Google Sheets (but not Excel) has a handy formula, REGEXREPLACE, that will let you do what you need:
=SUBSTITUTE(REGEXREPLACE(A1,"<b>|</b>|✔",""),"★","•")
If you need to remove any more characters, just add them after the checkmark, separated by |.
I would like to extract a line of strings but am having difficulties using the correct RegEx. Any help would be appreciated.
String to extract: KSEA 122053Z 21008KT 10SM FEW020 SCT250 17/08 A3044 RMK AO2 SLP313 T01720083 50005
For Some reason StackOverflow wont let me cut and paste the XML data here since it includes "<>" characters. Basically I am trying to extract data between "raw_text" ... "/raw_text" from a xml that will always be formatted like the following: http://www.aviationweather.gov/adds/dataserver_current/httpparam?dataSource=metars&requestType=retrieve&format=xml&hoursBeforeNow=3&mostRecent=true&stationString=PHNL%20KSEA
However, the Station name, in this case "KSEA" will not always be the same. It will change based on user input into a search variable.
Thanks In advance
if I can assume that every strings that you want starts with KSEA, then the answer would be:
.*(KSEA.*?)KSEA.*
using ? would let .* match as less as possible.
This seems like a simple one, but I am missing something.
I have a number of inputs coming in from a variety of sources and in different formats.
Number inputs
123
123.45
123,45 (note the comma used here to denote decimals)
1,234
1,234.56
12,345.67
12,345,67 (note the comma used here to denote decimals)
Additional info on the inputs
Numbers will always be less than 1 million
EDIT: These are prices, so will either be whole integers or go to the hundredths place
I am trying to write a regex and use gsub to strip out the thousands comma. How do I do this?
I wrote a regex: myregex = /\d+(,)\d{3}/
When I test it in Rubular, it shows that it captures the comma only in the test cases that I want.
But when I run gsub, I get an empty string: inputstr.gsub(myregex,"")
It looks like gsub is capturing everything, not just the comma in (). Where am I going wrong?
result = inputstr.gsub(/,(?=\d{3}\b)/, '')
removes commas only if exactly three digits follow.
(?=...) is a lookahead assertion: It needs to be possible to be matched at the current position, but it's not becoming part of the text that is actually matched (and subsequently replaced).
You are confusing "match" with "capture": to "capture" means to save something so you can refer to it later. You want to capture not the comma, but everything else, and then use the captured portions to build your substitution string.
Try
myregex = /(\d+),(\d{3})/
inputstr.gsub(myregex,'\1\2')
In your example, it is possible to tell from the number of digits after the last separator (either , or .) that it is a decimal point, since there are 2 lone digits. For most cases, if the last group of digits does not have 3 digits then you can assume that the separator in front is decimal point. Another sign is the multiple appearance of a separator in big numbers allows us to differentiate between decimal point and separators.
However, I can give a string 123,456 or 123.456 without any sort of context. It is impossible to tell whether they are "123 thousand 456" or "123 point 456".
You need to scan the document to look for clue whether , is used for thousand separator or decimal point, and vice versa for .. With the context provided, then you can safely apply the same method to remove the thousand separators.
You may also want to check out this article on Wikipedia on the less common ways to specify separators or decimal points. Knowing and deciding not to support is better than assuming things will work.
For coding reasons which would horrify you (I'm too embarrassed to say), I need to store a number of text items in a single string.
I will delimit them using a character.
Which character is best to use for this, i.e. which character is the least likely to appear in the text? Must be printable and probably less than 128 in ASCII to avoid locale issues.
I would choose "Unit Separator" ASCII code "US": ASCII 31 (0x1F)
In the old, old days, most things were done serially, without random access. This meant that a few control codes were embedded into ASCII.
ASCII 28 (0x1C) File Separator - Used to indicate separation between files on a data input stream.
ASCII 29 (0x1D) Group Separator - Used to indicate separation between tables on a data input stream (called groups back then).
ASCII 30 (0x1E) Record Separator - Used to indicate separation between records within a table (within a group). These roughly map to a tuple in modern nomenclature.
ASCII 31 (0x1F) Unit Separator - Used to indicate separation between units within a record. The roughly map to fields in modern nomenclature.
Unit Separator is in ASCII, and there is Unicode support for displaying it (typically a "us" in the same glyph) but many fonts don't display it.
If you must display it, I would recommend displaying it in-application, after it was parsed into fields.
Assuming for some embarrassing reason you can't use CSV I'd say go with the data. Take some sample data, and do a simple character count for each value 0-127. Choose one of the ones which doesn't occur. If there is too much choice get a bigger data set. It won't take much time to write, and you'll get the answer best for you.
The answer will be different for different problem domains, so | (pipe) is common in shell scripts, ^ is common in math formulae, and the same is probably true for most other characters.
I personally think I'd go for | (pipe) if given a choice but going with real data is safest.
And whatever you do, make sure you've worked out an escaping scheme!
When using different languages, this symbol: ¬
proved to be the best. However I'm still testing.
Probably | or ^ or ~ you could also combine two characters
You said "printable", but that can include characters such as a tab (0x09) or form feed (0x0c). I almost always choose tabs rather than commas for delimited files, since commas can sometimes appear in text.
(Interestingly enough the ascii table has characters GS (0x1D), RS (0x1E), and US (0x1F) for group, record, and unit separators, whatever those are/were.)
If by "printable" you mean a character that a user could recognize and easily type in, I would go for the pipe | symbol first, with a few other weird characters (# or ~ or ^ or \, or backtick which I can't seem to enter here) as a possibility. These characters +=!$%&*()-'":;<>,.?/ seem like they would be more likely to occur in user input. As for underscore _ and hash # and the brackets {}[] I don't know.
How about you use a CSV style format? Characters can be escaped in a standard CSV format, and there's already a lot of parsers already written.
Can you use a pipe symbol? That's usually the next most common delimiter after comma or tab delimited strings. It's unlikely most text would contain a pipe, and ord('|') returns 124 for me, so that seems to fit your requirements.
For fast escaping I use stuff like this:
say you want to concatinate str1, str2 and str3
what I do is:
delimitedStr=str1.Replace("#","#a").Replace("|","#p")+"|"+str2.Replace("#","#a").Replace("|","#p")+"|"+str3.Replace("#","#a").Replace("|","#p");
then to retrieve original use:
splitStr=delimitedStr.Split("|".ToCharArray());
str1=splitStr[0].Replace("#p","|").Replace("#a","#");
str2=splitStr[1].Replace("#p","|").Replace("#a","#");
str3=splitStr[2].Replace("#p","|").Replace("#a","#");
note: the order of the replace is important
its unbreakable and easy to implement
Pipe for the win! |
We use ascii 0x7f which is pseudo-printable and hardly ever comes up in regular usage.
Well it's going to depend on the nature of your text to some extent but a vertical bar 0x7C doesn't crop up in text very often.
I don't think I've ever seen an ampersand followed by a comma in natural text, but you can check the file first to see if it contains the delimiter, and if so, use an alternative. If you want to always be able to know that the delimiter you use will not cause a conflict, then do a loop checking the file for the delimiter you want, and if it exists, then double the string until the file no longer has a match. It doesn't matter if there are similar strings because your program will only look for exact delimiter matches.
This can be good or bad (usually bad) depending on the situation and language, but keep mind mind that you can always Base64 encode the whole thing. You then don't have to worry about escaping and unescaping various patterns on each side, and you can simply seperate and split strings based on a character which isn't used in your Base64 charset.
I have had to resort to this solution when faced with putting XML documents into XML properties/nodes. Properties can't have CDATA blocks in them at all, and nodes escaped as CDATA obviously cannot have further CDATA blocks inside that without breaking the structure.
CSV is probably a better idea for most situations, though.
Both pipe and caret are the obvious choices. I would note that if users are expected to type the entire response, caret is easier to find on any keyboard than is pipe.
I've used double pipe and double caret before. The idea of a non printable char works if your not hand creating or modifying the file. For quick random access file storage and retrieval field width is used. You don't even have to read the file.. your literally pulling from the file by reference. This is how databases do some storage.. but they also manage the spaces between records and such. And it introduced the problem of max data element width. (Index attach a header which is used to define the width of each element and it's data type in the original old days.. later they introduced compression with remapping chars. This allows for a text file to get about 1/8 the size in transmission.. variable length char encoding for the win
make it dynamic : )
announce your control characters in the file header
for example
delimiter: ~
escape: \
wrapline: $
width: 19
hello world~this i$
s \\just\\ a sampl$
e text~$someVar$~h$
ere is some \~\~ma$
rkdown strikethrou$
gh\~\~ text
would give the strings
hello world
this is \just\ a sample text
$someVar$
here is some ~~markdown strikethrough~~ text
i have implemented something similar:
a plaintar text container format,
to escape and wrap utf16 text in ascii,
as an alternative to mime multipart messages.
see https://github.com/milahu/live-diff-html-editor