XSLT fn:tokenize ignore leading and trailing spaces - xslt

Simple date string needs to be tokenized. I'am using this sample xslt code:
fn:tokenize(date, '[ .\s]+')
All variants of bad date format (i.e. "10.10.2020", "10. 10 .2020", "10 . 10. 2020") are tokenized ok using the function above, except if there's a leading space present (i.e. " 10.10.2020"). If leading space is present, first element is then tokenized as " " blank space.
Is there an option to ignore these leading spaces as well so no matter how bad the format is, only delimiter "." means another token and all spaces are stripped as well?

The right solution seems to be:
fn:tokenize(normalize-space(date, '[ .\s]+')

Related

SUM multiple values after a substring within all cells in a column in Google Sheets

For an open source chat analyser in Google Sheets, I need to extract all numeric values after a substring (Example), then total them.
For example, if a cell contains Example1 another text 123 Example500 text, Example1 and Example500 should be extracted out, and their numeric values summed to 501.
This is complicated further by needing to obtain the total for a column of messages.
What I've tried already:
=REGEXEXTRACT(A1, "Example(\d+)"): This only extracts the first matching value, but works!
=SUM(SPLIT(A1, "Example")): This works for messages that only include my target string, but falls apart when other strings are included. The output could possibly be filtered to results that start with a number, but this is very messy and possibly a red herring.
CONCATENATEing all my cells together, then searching for numbers. This is error-prone due to additional numbers within messages.
Another idea is to substitute each Example(\d+) to $1 the captured digit and space |. or replace anything else with empty string (regex101 demo). Knowing that $1 is unset on the right side of the alternation. Then split on space and sum up digits (any other occurring digits have been removed). If Example is a placeholder, replace with e.g. [[:alpha:]]+ for one or more alphabetic characters.
=IF(ISTEXT(A1);SUM(SPLIT(REGEXREPLACE(A1;"Example(\d+)|.";"$1 ");" "));0)
I added IF(ISTEXT(A1);...) for only processing text in the source field (to avoid errors). Else if empty or no text it's set to 0. Just remove if the field always contains text and this is unneeded.
Edit from #TheMaster: As a array formula, we can use BYROW
=BYROW(A:A; LAMBDA(row; IF(ISTEXT(row); SUM(SPLIT(
REGEXREPLACE(row;"Example(\d+)|.";"$1 ");" "));)))
try:
=LAMBDA(x, REGEXEXTRACT(A1, "(\w+)\d+")&
SUMPRODUCT(IF(IFERROR(REGEXMATCH(x, "\w+\d+")),
REGEXEXTRACT(x, "\w+(\d+)"), )))(SPLIT(A1, " "))
update 1:
=LAMBDA(x, REGEXEXTRACT(A1, "(\D+)\d+")&
SUMPRODUCT(IF(IFERROR(REGEXMATCH(x, "\D+\d+")),
REGEXEXTRACT(x, "\D+(\d+)"), )))(SPLIT(A1, " "))
update 2:
=INDEX(LAMBDA(xx, REGEXEXTRACT(xx, "(\D+)\d+")&
BYROW(LAMBDA(x, IF(IFERROR(REGEXMATCH(x, "\D+\d+")),
REGEXEXTRACT(x, "\D+(\d+)"), ))(SPLIT(xx, " ")), LAMBDA(x, SUMPRODUCT(x))))
(A1:INDEX(A:A, MAX((A:A<>"")*ROW(A:A)))))
if you start from A2 just change A1: to A2:

Tcl - How to Add Text after last character through regex?

I need a tip, tip or suggestion followed by some example of how I can add an extension in .txt format after the last character of a variable's output line.
For example:
set txt " ONLINE ENGLISH COURSE - LESSON 5 "
set result [concat "$txt" .txt]
Print:
Note that there is space in the start, means and fin of the variable phrase (txt). What must be maintained are the spaces of the start and means. But replace the last space after the end of the sentence, with the format of the extension [.txt].
With the built-in concat method of Tcl, it does not achieve the desired effect.
The expected result was something like this:
ONLINE ENGLISH COURSE - LESSON 5.txt
I know I could remove spaces with string map but I don't know how to remove just the last occurrence on the line.
And otherwise I don’t know how to remove the last space to add the text [.txt]
If anyone can point me to one or more solutions, thank you in advance.
set result "[string trimright $txt].txt"
or
set result [regsub {\s*$} $txt ".txt"]

SAS treatment of blanks interferes with regex rules

I have a dataset which I need to clean using regex rules. These rules come from a file regex_rules.csv with columns string_pattern and string_replace and are applied using a combination of prxparse and prxchange as follows:
array a_rules{1:&NOBS} $200. _temporary_;
array a_rules_parsed{1:&num_rules} _temporary_;
if _n_ = 1 then
do i = 1 to &num_rules;
a_rules{i} = cat("'s/",string_pattern,"/",string_replace,"/'");
a_rules_parsed{i} = prxparse(cats('s/',string_pattern,'/',string_replace,'/','i'));
end
set work.dirty_strings;
clean_string = dirty_string;
do i = 1 to &num_rules;
debug_string = cats("Executing prxchange(",a_rules{i},",",-1,",","'",clean_string,"'",")");
put debug_string;
clean_string = PRXCHANGE(a_rules_parsed{i},-1,clean_string);
end
Some rules specify replacing certain patterns with a single blank space, so the corresponding string_replace value in the file is a single blank space.
The issue I'm facing is that SAS never respects the single space, and instead replaces the matched string_pattern for these records with an empty string (the other rules are applied as expected).
To troubleshoot I executed the following:
proc sql;
create table work.single_blanks as
select
string_pattern,
string_replace,
from work.regex_rules
where string_replace = " ";
quit;
which yielded the expected records. I was confused to find that changing the where clause to
where string_replace = "" or
where string_replace = " " gave identical results! (I've been using sas for a while but I guess this behavior has gone unnoticed until now). Consequently, I could not determine whether SAS is neglecting to properly read in the file and retain the single blank, or whether one of the prx functions is failing to properly handle the single blank.
I can think of "hacky" work-arounds, but I'd rather understand what I'm doing wrong here and what the correct solution should be.
EDIT 1:
Here is a rule from the file and how I'd expect it to act on an example input value:
string_pattern, string_replace
"(#|,|/|')", " "
running the code above on the input string dirty_string = "10,120 DIRTY DRIVE"; does not produce the expected output of "10 120 DIRTY DRIVE" but rather "10120 DIRTY DRIVE".
EDIT 2
In addition to not respecting single spaces, leading and trailing spaces do not seem to be respected. For example, for a file with the rules
string_pattern, string_replace
"\\bDR(\\.|\\b)", "DRIVE "
"\\bS(\\.|\\b)?W(\\.|\\b)", " SOUTH WEST"
running the code above on the input string dirty_string = "10120 DIRTY DR.SW."; does not produce the expected output of "10120 DIRTY DRIVE SOUTH WEST" but rather "10120 DIRTY DRIVESW.". This is because the space at the end of the first string_replace value gets lost, meaning there is no word boundary at the beginning of the second string_pattern to be matched.
SAS stores character variables as fixed length strings that are padded with spaces. As a consequence string comparisons ignore trailing spaces. So x=' ' and x=' ' are the same test.
The CATS() will remove all of the leading and trailing spaces, so empty strings will generate nothing at all. It sounds like you want to treat an empty string as a single space. The TRIM() function will return a single space for an empty string. So perhaps you just want to change this:
cats('s/',string_pattern,'/',string_replace,'/','i')
into
cat('s/',trim(string_pattern),'/',trim(string_replace),'/','i')
Here is a working code (with a fixed string_pattern) of your example data:
data test;
length string_pattern string_replace dirty_string expect
clean_string regex $200
;
infile cards dsd truncover;
input string_pattern string_replace dirty_string expect;
regex= cat('s/',trim(string_pattern),'/',trim(string_replace),'/i') ;
regex_id = prxparse(trim(regex));
clean_string = prxchange(regex_id,-1,trim(dirty_string));
if clean_string=expect then put 'GOOD'; else put 'BAD';
*put (_character_) (=$quote./);
cards4;
"(#|,|\/|')", " ","10,120 DIRTY DRIVE","10 120 DIRTY DRIVE"
;;;;
If any of your values have significant trailing spaces then you will need to store the data differently. You could for example quote the values:
string_replace = "'DRIVE '";
...
cat('s/',dequote(string_pattern),'/',dequote(string_replace),'/','i')
If you only add quotes around values that need them then you will need to include the TRIM() function calls.
cat('s/',dequote(trim(string_pattern)),'/',dequote(trim(string_replace)),'/','i')
Or store the string lengths into separate numeric fields.
cat('s/',substrn(string_pattern,1,len1),'/',substrn(string_replace,1,len2),'/','i')
And note that if any of your original character strings had either significant leading or trailing spaces they would have been eliminated by reading the data from a CSV file.

Extract a text string with regex

I have a large set of data I need to clean with open refine.
I am quite bad with regex and I can't think of a way to get what I want,
which is extracting a text string between quotes that includes lots of special characters like " ' / \ # # -
In each cell, it has the same format
caption': u'text I want to extract', u'likes':
Any help would be highly appreciated!
If you want to extract text string that includes lots of special characters in between, and is located between quotes ' ', You can do it in general this way:
\'[\S\s]*?\'
Demo
.
In your case, if you want to extract only the medial quote from this: caption': u'text I want to extract', u'likes': , Try this Regex:
(?<=u\')[\V]*?(?=\'\,)
Demo
We designed OpenRefine with a few smart functions to handle common cases such as yours without using Regex.
Two other cool ways to handle this in OpenRefine.
Using drop down menu:
Edit Column
Split into several columns
by separator Separator '
Using smartSplit
(string s, optional string sep)
returns: array
Returns the array of strings obtained by splitting s with separator sep. Handles quotes properly. Guesses tab or comma separator if "sep" is not given.
value.smartSplit("'")[2]

Strategy to replace spaces in string

I need to store a string replacing its spaces with some character. When I retrieve it back I need to replace the character with spaces again. I have thought of this strategy while storing I will replace (space with _a) and (_a with _aa) and while retrieving will replace (_a with space) and (_aa with _a). i.e even if the user enters _a in the string it will be handled. But I dont think this is a good strategy. Please let me know if anyone has a better one?
Replacing spaces with something is a problem when something is already in the string. Why don't you simply encode the string - there are many ways to do that, one is to convert all characters to hexadecimal.
For instance
Hello world!
is encoded as
48656c6c6f20776f726c6421
The space is 0x20. Then you simply decode back (hex to ascii) the string.
This way there are no space in the encoded string.
-- Edit - optimization --
You replace all % and all spaces in the string with %xx where xx is the hex code of the character.
For instance
Wine having 12% alcohol
becomes
Wine%20having%2012%25%20alcohol
%20 is space
%25 is the % character
This way, neither % nor (space) are a problem anymore - Decoding is easy.
Encoding algorithm
- replace all `%` with `%25`
- replace all ` ` with `%20`
Decoding algorithm
- replace all `%xx` with the character having `xx` as hex code
(You may even optimize more since you need to encode only two characters: use %1 for % and %2 for , but I recommend the %xx solution as it is more portable - and may be utilized later on if you need to code more characters)
I'm not sure your solution will work. When reading, how would you
distinguish between strings that were orginally " a" and strings that
were originally "_a": if I understand correctly, both will end up
"_aa".
In general, given a situation were a specific set of characters cannot
appear as such, but must be encoded, the solution is to choose one of
allowed characters as an "escape" character, remove it from the set of
allowed characters, and encode all of the forbidden characters
(including the escape character) as a two (or more) character sequence
starting with the escape character. In C++, for example, a new line is
not allowed in a string or character literal. The escape character is
\; because of that, it must be encoded as an escape sequence as well.
So we have "\n" for a new line (the choice of n is arbitrary), and
"\\" for a \. (The choice of \ for the second character is also
arbitrary, but it is fairly usual to use the escape character, escaped,
to represent itself.) In your case, if you want to use _ as the
escape character, and "_a" to represent a space, the logical choice
would be "__" to represent a _ (but I'd suggest something a little
more visually suggestive—maybe ^ as the escape, with "^_" for
a space and "^^" for a ^). When reading, anytime you see the escape
character, the following character must be mapped (and if it isn't one
of the predefined mappings, the input text is in error). This is simple
to implement, and very reliable; about the only disadvantage is that in
an extreme case, it can double the size of your string.
You want to implement this using C/C++? I think you should split your string into multiple part, separated by space.
If your string is like this : "a__b" (multiple space continuous), it will be splited into:
sub[0] = "a";
sub[1] = "";
sub[2] = "b";
Hope this will help!
With a normal string, using X characters, you cannot write or encode a string with x-1 using only 1 character/input character.
You can use a combination of 2 chars to replace a given character (this is exactly what you are trying in your example).
To do this, loop through your string to count the appearances of a space combined with its length, make a new character array and replace these spaces with "//" this is just an example though. The problem with this approach is that you cannot have "//" in your input string.
Another approach would be to use a rarely used char, for example "^" to replace the spaces.
The last approach, popular in a combination of these two approaches. It is used in unix, and php to have syntax character as a literal in a string. If you want to have a " " ", you simply write it as \" etc.
Why don't you use Replace function
String* stringWithoutSpace= stringWithSpace->Replace(S" ", S"replacementCharOrText");
So now stringWithoutSpace contains no spaces. When you want to put those spaces back,
String* stringWithSpacesBack= stringWithoutSpace ->Replace(S"replacementCharOrText", S" ");
I think just coding to ascii hexadecimal is a neat idea, but of course doubles the amount of storage needed.
If you want to do this using less memory, then you will need two-letter sequences, and have to be careful that you can go back easily.
You could e.g. replace blank by _a, but you also need to take care of your escape character _. To do this, replace every _ by __ (two underscores). You need to scan through the string once and do both replacements simultaneously.
This way, in the resulting text all original underscores will be doubled, and the only other occurence of an underscore will be in the combination _a. You can safely translate this back. Whenever you see an underscore, you need a lookahed of 1 and see what follows. If an a follows, then this was a blank before. If _ follows, then it was an underscore before.
Note that the point is to replace your escape character (_) in the original string, and not the character sequence to which you map the blank. Your idea with replacing _a breaks. as you do not know if _aa was originally _a or a (blank followed by a).
I'm guessing that there is more to this question than appears; for example, that you the strings you are storing must not only be free of spaces, but they must also look like words or some such. You should be clear about your requirements (and you might consider satisfying the curiosity of the spectators by explaining why you need to do such things.)
Edit: As JamesKanze points out in a comment, the following won't work in the case where you can have more than one consecutive space. But I'll leave it here anyway, for historical reference. (I modified it to compress consecutive spaces, so it at least produces unambiguous output.)
std::string out;
char prev = 0;
for (char ch : in) {
if (ch == ' ') {
if (prev != ' ') out.push_back('_');
} else {
if (prev == '_' && ch != '_') out.push_back('_');
out.push_back(ch);
}
prev = ch;
}
if (prev == '_') out.push_back('_');