I have s string that looks like
txt = '"EMB","iShares J,P. Morg",110.81,N/A'
I'm using strsplit(txt,','); to break this into separate strings based on the comma delimiter. However I want to ignore the comma between the 'J' and the 'P', since it's not a delimiter; it's just part of the name.
Is there a way I can say "if a comma is between two quotes but there are other characters between the quotes, delete the comma"?
Here's an equivalent regexp one-liner:
C = regexp(txt, '("[^"]*")|([^,"]+)', 'match')
The result is a cell array with already split strings. Unfortunately, I don't have MATLAB R2013, so I cannot benchmark this versus strsplit.
A silly (but functional) answer:
inquotes=false;
keep=true(1,length(txt));
for v=1:length(txt)
if (txt(v)=='"')
inquotes=~inquotes;
elseif (txt(v)==',' && inquotes)
keep(v)=false;
end
end
txt=txt(keep);
tt=strsplit(txt,',');
This will, if you are in quotes, remove the commas so that you can use strsplit. That is what I understood you want to do, correct?
Related
I've been struggling to get all items of below string into an array.
abc,"de,f",hi,"hello","te,st&" items into an array in Typescript.
If any string has comma (,) or ampersand (&) in it,It will be placed in double quotes.
Tried split function but it fails as my strings can have comma as well.
Any help in this regard is highly appreciated.
Thank you.
If you are looking to use a regular expression matching, can you try a different regEx that would match strings inside quotes first, then strings outside quotes, something like (\".+?\")|(^[^\"]+,)|(,[^\"]+,)
I don't know how relevant it would be in case of TypeScript, but I am guessing you'd be able to work something out that takes this Pattern and gives you the matches one by one
First of all, I think that you are making the things more complicated than what they are by implementing the following logic:
has comma (,) or ampersand (&) in it,It will be placed in double quotes.
Instead of doing this that way, you should systematically put your elements inside double quote:
abc,"de,f",hi,"hello","te,st&"
→
"abc","de,f","hi","hello","te,st&"
you will have then the following string to parse.
A regex like this one will do the job:
(?<=,")([^"]*)(?=",)|(?<=")([^"]*)(?=",)|(?<=")([^"]*)(?="$)
using back references $1$2$3, you can extract your elements.
RegEx /(?:^|,)(\"(?:[^\"])\"|[^,])/ has helped me get the required values.
var test = '"abc,123",test,123,456,"def:get"';
test.split(/(\"(?:[^\"])\"|[^,])/);
Its returning the below array.
["", ""abc,123"", ",", "test", ",", "123", ",", "456", ",", ""def:get"", ""]
And when a particular values in side double quotes,I just trimmed them to get the actual values and have ignore empty items of array..
use the split a string .....
let fullName = "First,Last"
let fullNameArr = fullName.characters.split{$0 == ","}.map(String.init)
fullNameArr[0] // First
fullNameArr[1] // Last
In a .csv file I have lines like the following :
10,"nikhil,khandare","sachin","rahul",viru
I want to split line using comma (,). However I don't want to split words between double quotes (" "). If I split using comma I will get array with the following items:
10
nikhil
khandare
sachin
rahul
viru
But I don't want the items between double-quotes to be split by comma. My desired result is:
10
nikhil,khandare
sachin
rahul
viru
Please help me to sort this out.
The character used for separating fields should not be present in the fields themselves. If possible, replace , with ; for separating fields in the csv file, it'll make your life easier. But if you're stuck with using , as separator, you can split each line using this regular expression:
/((?:[^,"]|"[^"]*")+)/
For example, in Python:
import re
s = '10,"nikhil,khandare","sachin","rahul",viru'
re.split(r'((?:[^,"]|"[^"]*")+)', s)[1::2]
=> ['10', '"nikhil,khandare"', '"sachin"', '"rahul"', 'viru']
Now to get the exact result shown in the question, we only need to remove those extra " characters:
[e.strip('" ') for e in re.split(r'((?:[^,"]|"[^"]*")+)', s)[1::2]]
=> ['10', 'nikhil,khandare', 'sachin', 'rahul', 'viru']
If you really have such a simple structure always, you can use splitting with "," (yes, with quotes) after discarding first number and comma
If no, you can use a very simple form of state machine parsing your input from left to right. You will have two states: insides quotes and outside. Regular expressions is a also a good (and simpler) way if you already know them (as they are basically an equivalent of state machine, just in another form)
I need to use RegEx to run through a string of text but only return that parts that I need. Let's say for example the string is as follows:
1234,Weapon Types,100,Handgun,"This is the text, "and", that is all."""
\d*,Weapon Types,(\d*),(\w+), gets me most of the way, however it is the last part that I am having an issue with. Is there a way for me to capture the rest of the string i.e.
"This is the text, "and", that is all."""
without picking up the quotes? I've tried negating them, however it just stops the string at the quote.
Please keep in mind that the text for this string is unknown so doing literal matches will not work.
You've given us something very difficult to solve. It's okay that you have nested commas inside your string. Once we come across a double-quote, we can ignore everything until the end quote. This would gooble up commas.
But how will your parser know that the next double-quote isn't ending the string. How does it know that it a nested double-quote?
If I could slightly modify your input string to make it clear what is a nested quote, then parsing is easy...
var txt = "1234,Weapon Types,100,Handgun,\"This is the text, "and", that is all.\",other stuff";
var m = Regex.Match(txt, #"^\d*,Weapon Types,(\d*),(\w+),""([^""]+)""");
MessageBox.Show(m.Groups[3].Value);
But if your input string must have nested quotes like that, then we must come up with some other rule for detecting what is the real end of the string. How about this?
var txt = "1234,Weapon Types,100,Handgun,\"This is the text, \"and\", that is all.\",other stuff";
var m = Regex.Match(txt, #"^\d*,Weapon Types,(\d*),(\w+),""(.+)"",");
MessageBox.Show(m.Groups[3].Value);
The result is...
This is the text, "and", that is all.
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('_');
In my opinion, Vimscript does not have a lot of features for manipulating strings.
I often use matchstr(), substitute(), and less often strpart().
Perhaps there is more than that.
For example, what is the best way to remove all text between line numbers in the following string a?
let a = "\%8l............\|\%11l..........\|\%17l.........\|\%20l...." " etc.
I want to keep only the digits and put them in a list:
['8', '11', '17', '20'] " etc.
(Note that the text between line numbers can be different.)
You're looking for split()
echo split(a, '[^0-9]\+')
EDIT:
Given the new constraint: only the numbers from \%d\+l, I'd do:
echo map(split(a, '|'), "matchstr(v:val, '^%\\zs\\d\\+\\zel')")
NB: your vim variable is incorrectly formatted, to use only one backslash, you'd need to write your string with single-quotes. With double-quotes, here you'd need two backslashes.
So, with
let b = '\%8l............\|\%11l..........\|\%17l.........\|\%20l....'
it becomes
echo map(split(b, '\\|'), "matchstr(v:val, '^\\\\%\\zs\\d\\+\\zel')")
One can take advantage of the substitute with an expression feature (see
:help sub-replace-\=) to run over all of the target matches, appending them
to a list.
:let l=[] | call substitute(a, '\\%\(\d\+\)l', '\=add(l,submatch(1))[1:0]', 'g')