Friends:
I have to process a CSV file, using Perl language and produce an Excel as output, using the Excel::Writer::XSLX module. This is not a homework but a real life problem, where I cannot download whichever Perl version (actually, I need to use Perl 5.6), or whichever Perl module (I have a limited set of them). My OS is UNIX. I can also use (embedding in Perl) ksh and csh (with some limitation, as I have found so far). Please, limit your answers to the tools I have available. Thanks in advance!
Even though I am not a Perl developer, but coming from other languages, I have already done my work. However, the customer is asking for extra processing where I am getting stuck on.
1) The stones in the road I found are coming from two sides: from Perl and from Excel particular styles of processing data. I already found a workaround to handle the Excel, but -as mentioned in the subject- I have difficulties while processing zeroes found in CSV input file. To handle the Excel, I am using the '0 way which is the final way for data representation that Excel seems to have while using the # formatting style.
2) Scenario:
I need to catch standalone zeroes which might be present in whichever line / column / cell of the CSV input file and put them as such (as zeroes) in the Excel output file.
I will go directly to the point of my question to avoid loosing your valuable time. I am providing more details after my question:
Research and question:
I tried to use Perl regex to find standalone "0" and replace them by whichever string, planning to replace them back to "0" at the end of processing.
perl -p -i -e 's/\b0\b/string/g' myfile.csv`
and
perl -i -ple 's/\b0\b/string/g' myfile.csv
Are working; but only from command line. They aren't working when I call them from the Perl script as follows:
system("perl -i -ple 's/\b0\b/string/g' myfile.csv")
Do not know why... I have already tried using exec and eval, instead of system, with the same results.
Note that I have a ton of regex that work perfectly with the same structure, such as the following:
system("perl -i -ple 's/input/output/g' myfile.csv")
I have also tried using backticks and qx//, without success. Note that qx// and backticks have not the same behavior, since qx// is complaining about the boundaries \b because of the forward slash.
I have tried using sed -i, but my System is rejecting -i as invalid flag (do not know if this happens in all UNIX, but at least happens in the one at work. However is accepting perl -i).
I have tried embedding awk (which is working from command line), in this way:
system `awk -F ',' -v OFS=',' '$1 == \"0\" { $1 = "string" }1' myfile.csv > myfile_copy.csv
But this works only for the first column (in command line) and, other than having the disadvantage of having extra copy file, Perl is complaining for > redirection, assuming it as "greater than"...
system(q#awk 'BEGIN{FS=OFS=",";split("1 2 3 4 5",A," ") } { for(i in A)sub(0,"string",$A[i] ) }1' myfile.csv#);
This awk is working from command line, but only 5 columns. But not in Perl using #.
All the combinations of exec and eval have also been tested without success.
I have also tried passing to system each one of the awk components, as arguments, separated by commas, but did not find any valid way to pass the redirector (>), since Perl is rejecting it because of the mentioned reason.
Using another approach, I noticed that the "standalone zeroes" seem to be "swallowed" by the Text::CSV module, thus, I get rid off it, and turned back to a traditional looping in csv line by line and a spliter for commas, preserving the zeroes in that way. However I found the "mystery" of isdual in Perl, and because of the limitation of modules I have, I cannot use the Dumper. Then, I also explored the guts of binaries in Perl and tried the $x ^ $x, which was deprecated since version 5.22 but valid till that version (I said mine is 5.6). This is useful to catch numbers vs strings. However, while if( $x ^ $x ) returns TRUE for strings, if( !( $x ^ $x ) ) does not returns TRUE when $x = 0. [UPDATE: I tried this in a devoted Perl script, just for this purpose, and it is working. I believe that my probable wrong conclusion ("not returning TRUE") was obtained when I did not still realize that Text::CSV was swallowing my zeroes. Doing new tests...].
I will appreciate very much your help!
MORE DETAILS ON MY REQUIREMENTS:
1) This is a dynamic report coming from a database which is handover to me and I pickup programmatically from a folder. Dynamic means that it might have whichever amount of tables, whichever amount of columns in each table, whichever names as column headers, whichever amount of rows in each table.
2) I do not know, and cannot know, the column names, because they vary from report to report. So, I cannot be guided by column names.
A sample input:
Alfa,Alfa1,Beta,Gamma,Delta,Delta1,Epsilon,Dseta,Heta,Zeta,Iota,Kappa
0,J5,alfa,0,111.33,124.45,0,0,456.85,234.56,798.43,330000.00
M1,0,X888,ZZ,222.44,111.33,12.24,45.67,0,234.56,0,975.33
3) Input Explanation
a) This is an example of a random report with 12 columns and 3 rows. Fist row is header.
b) I call "standalone zeroes" those "clean" zeroes which are coming in the CSV file, from second row onwards, between commas, like 0, (if the case is the first position in the row) or like ,0, in subsequent positions.
c) In the second row of the example you can read, from the beginning of the row: 0,J5,alfa,0, which in this particular case, are "words" or "strings". In this case, 4 names (note that two of them are zeroes, which required to be treated as strings). Thus, we have a 4 names-columns example (Alfa,Alfa1,Beta,Gamma are headers for those columns, but only in this scenario). From that point onwards, in the second row, you can see floating point (*.00) numbers and, among them, you can see 2 zeroes, which are numbers. Finally, in the third line, you can read M1,0,X888,Z, which are the names for the first 4 columns. Note, please, that the 4th column in the second row has 0 as name, while the 4th column in the third row has ZZ as name.
Summary: as a general picture, I have a table-report divided in 2 parts, from left to right: 4 columns for names, and 8 columns for numbers.
Always the first M columns are names and the last N columns are numbers.
- It is unknown which number is M: which amount of columns devoted for words / strings I will receive.
- It is unknown which number is N: which amount of columns devoted for numbers I will receive.
- It is KNOWN that, after the M amount of columns ends, always starts N, and this is constant for all the rows.
I have done a quick research on Perl boundaries for regex ( \b ), and I have not found any relevant information regarding if it applies or not in Perl 5.6.
However, since you are using and old Perl version, try the traditional UNIX / Linux style (I mean, what Perl inherits from Shell), like this:
system("perl -i -ple 's/^0/string/g' myfile.csv");
The previous regex should do the work doing the change at the start of the each line in your CSV file, if matches.
Or, maybe better (if you have those "standalone" zeroes, and want avoid any unwanted change in some "leading zeroes" string):
system("perl -i -ple 's/^0,/string,/g' myfile.csv");
[Note that I have added the comma, after the zero; and, of course, after the string].
Note that the first regex should work; the second one is just a "caveat", to be cautious.
I've been trying to develop a program that will be used for DMing in an MMORPG but I'm having trouble parsing for the actual regex expression I need.
To quote myself from another thread on a less active forum:
I've officially taken over the DiceRoller addon from years and years ago and I've reworked it a lot since I've taken it over and done a lot of testing in game. While I haven't uploaded anything yet, I've been struggling on a piece of regex expression that is currently crucial to the design of the addon.
Some background: the newest iteration of the DiceRoller addon makes it so you can type "!XdY" (where X is the number of dice, Y is the dice value) into raid chat and the DM who has the addon will go through some logic in the addon (random number lua protocol) and then spit out an input after adding up the dice.
It is as follows:
local count, size = string.match(message, "^!(%d+)[dD](%d+)$")
Now the functionality I need it to do is parse for both "!XdY" OR "XdY+Z", but it seems as if I can't get close to "XdY+Z" no matter which regex expression I use since I need it to do both expressions. I can provide more source code context if necessary.
This is the closest I've ever gotten:
http://i.imgur.com/eMhPHQB.png
and this is with the regex expression:
local count, size, modifier = string.match(message, "^!(%d+)[dD](%d+)+?(%d+)$")
As you can see, with the modifier it will work just fine. However, remove the modifier the regex expression still thinks that it is "XdY+Z" and so with "1d20" it think it is "1d2+0". It will think 1d200 is "1d20+0", etc. I've tried moving around the optional character "?" but it just causes the expression to not work at all. If I do !1d2 it doesn't work. It's almost as if the optional character NEEDS to be there?
Thanks for the help ahead of time, I've always struggled with regex.
local function dice(input)
local count, size, modifier = input:match"^!(%d+)[dD](%d+)%+?(%d*)$"
if count then
return tonumber(count), tonumber(size), tonumber("0"..modifier)
end
end
for _, input in ipairs{"!1d6", "!1d24", "!1d200", "!1d2+4", "!1d20+24"} do
print(input, dice(input))
end
Output:
!1d6 1 6 0
!1d24 1 24 0
!1d200 1 200 0
!1d2+4 1 2 4
!1d20+24 1 20 24
Lua regular expressions are very limited. You would need to use ^!(%d+)[dD](%d+)(?:+(%d+))?$ but this wouldn't be supported because of (?:+(%d+))? that uses a non-capturing group and a modifier on a group, both are not supported by Lua Patterns.
Consider using a regex library like this one that allows you to use PCRE, PHP regex engine, one of the most complete engine. But that would be overkill if you only want to use it for this regex. You can do it by code then, wouldn't be so hard for a simple task like this.
While Lua patterns are not powerful enough to parse this with one expression (as they don't support optional groups), there is an easy option to handle it with two expressions:
-- check the longer expression first
local count, size, modifier = string.match(message, "^!(%d+)[dD](%d+)+(%d+)$")
if not count then
count, size = string.match(message, "^!(%d+)[dD](%d+)$")
end
Given the following file path:
/Users/Lawrence/MyProject/some/very/interesting/Code.scala
I would like to generate the following using a single regex replace (the root can be a constant):
some.very.interesting
This is for the purpose of generating a snippet for Sublime Text which can automatically insert the correct package/namespace header for my scala/java classes :)
Sublime Text uses the following syntax for their regex replace patterns (aka 'substitutions'):
{input/regex/replace/flags}
Hence why an iterative approach cannot be taken - it has to be done in one pass! Also, substitutions cannot be nested :(
If you know the maximum number of nested folders.You can specify that in your regex.
For 1 to 3 nested folders
Regex:/Users/Lawrence/MyProject/(\w+)/?(\w+)?/?(\w+)?/[^/]+$
Replace:$1.$2.$3
For 1 to 5 nested folders
Regex:/Users/Lawrence/MyProject/(\w+)/?(\w+)?/?(\w+)?/?(\w+)?/?(\w+)?/[^/]+$
Replace:$1.$2.$3.$4.$5
Given the constraints this is only thing you can do
Input
/Users/Lawrence/MyProject/some/very/interesting/Code.scala
Regex
^/Users/Lawrence/MyProject/[^/]+/[^/]+/[^/]+/Code.scala
or
^/[^/]+/[^/]+/[^/]+/([^/]+)/([^/]+)/([^/]+)/
Replace
\1.\2.\3
Update
This gets you closer, but not exactly it:
Regex
(^/Users/Lawrence/MyProject/|/Code\.scala$|/)
Replacement
.
Output would be:
.some.very.interesting.
Without multiple replacements in a single line and without recursive back references it's going to be hard.
You might have to do a second replacement, replacing something like this with an empty string (if you can):
(^\.|\.$)
I am curently busy with bulding a synthax document in SPSS and have a column of variable strings that consists of approximately 40 lines (it will be much much more in coming week). SPSS has a nice way of creating it (can be seen here :)
http://vault.hanover.edu/~altermattw/methods/stats/reliable/reliability-1.html) but it can be done per one variable at a time which is possible to automatize.
I am a total beginner (I wouldn't mind if you would call me n00b) at search&replace with reqular expressions in notepad++ but I can use the extended search function as a basic user :P
The data contains scores Likert scale (from 1-7) and I would like to reverse it to do some tests.
For example: my variable name on the line is q_4_SQ001 and the sline in synthax editor is q_4_SQ001=COMPUTE q_4_SQ001r=8-q_4_SQ001.
My question so far is thus:
How can I convert a line containing a unique variable name into it's revers formula?
So in this case, how can I replace the following lines:
q_4_SQ001
q_4_SQ002
q_4_SQ003
q_4_SQ004
into the synthax given under:
COMPUTE q_4_SQ001r=8-q_4_SQ001.
COMPUTE q_4_SQ002r=8-q_4_SQ002.
COMPUTE q_4_SQ003r=8-q_4_SQ003.
COMPUTE q_4_SQ004r=8-q_4_SQ004.
Please remark the dots in the end of each line I did this manually to give you an impression of what I would like to achieve. My data set has different questions and different variable strings so I would like to make my life a bit easier right now :P
I also tried recording and running a macro as stated in here (http://stackoverflow.com/questions/2467875/notepad-replace-all-regular-expression-start-of-the-line-and-end-of-the-line) but that still is pretty time consuming since I have to do each line manulally and clean up with extended search in the end.
Wouldn't it be easier to convert each line?
Thanks a bunch in advance :)
Funny, Notepad++ works under Wine, as I just found out ;)
New file, inserted:
q_4_SQ001
q_4_SQ002
q_4_SQ003
q_4_SQ004
Select all (CTRL+A), replace (CTRL+R).
Tick Regular Expr, stick ^(.*)$ in the "find" bit (first textbox), and COMPUTE \1r=8-\1. in the "replace" bit (second textbox). Hit the Find button, and then the Replace Rest button.
Parenthesis () around a pattern cause the pattern to be "memorised", each set of parenthesis available to the replacement pattern via \1, \2, etc.
After the replace, I got:
COMPUTE q_4_SQ001r=8-q_4_SQ001.
COMPUTE q_4_SQ002r=8-q_4_SQ002.
COMPUTE q_4_SQ003r=8-q_4_SQ003.
COMPUTE q_4_SQ004r=8-q_4_SQ004.
Which I assume is what you wanted. Enjoy.
Intro
I work in a facility where we have microscopes. These guys can be asked to generate 4D movies of a sample: they take e.g. 10 pictures at different Z position, then wait a certain amount of time (next timepoint) and take 10 slices again.
They can be asked to save a file for each slice, and they use an explicit naming pattern, something like 2009-11-03-experiment1-Z07-T42.tif. The file names are numbered to reflect the Z position and the time point
Question
Once you have all these file names, you can use a regex pattern to extract the Z and T value, if you know the backbone pattern of the file name. This I know how to do.
The question I have is: do you know a way to automatically generate regex pattern from the file name list? For instance, there is an awesome tool on the net that does similar thing: txt2re.
What algorithm would you use to parse all the file name list and generate a most likely regex pattern?
There is a Perl module called String::Diff which has the ability to generate a regular expression for two different strings. The example it gives is
my $diff = String::Diff::diff_regexp('this is Perl', 'this is Ruby');
print "$diff\n";
outputs:
this\ is\ (?:Perl|Ruby)
Maybe you could feed pairs of filenames into this kind of thing to get an initial regex. However, this wouldn't give you capturing of numbers etc. so it wouldn't be completely automatic. After getting the diff you would have to hand-edit or do some kind of substitution to get a working final regex.
First of all, you are trying to do this the hard way. I suspect that this may not be impossible but you would have to apply some artificial intelligence techniques and it would be far more complicated than it is worth. Either neural networks or a genetic algorithm system could be trained to recognize the Z numbers and T numbers, assuming that the format of Z[0-9]+ and T[0-9]+ is always used somewhere in the regex.
What I would do with this problem is to write a Python script to process all of the filenames. In this script, I would match twice against the filename, one time looking for Z[0-9]+ and one time looking for T[0-9]+. Each time I would count the matches for Z-numbers and T-numbers.
I would keep four other counters with running totals, two for Z-numbers and two for T-numbers. Each pair would represent the count of filenames with 1 match, and the ones with multiple matches. And I would count the total number of filenames processed.
At the end, I would report as follows:
nnnnnnnnnn filenames processed
Z-numbers matched only once in nnnnnnnnnn filenames.
Z-numbers matched multiple times in nnnnnn filenames.
T-numbers matched only once in nnnnnnnnnn filenames.
T-numbers matched multiple times in nnnnnn filenames.
If you are lucky, there will be no multiple matches at all, and you could use the regexes above to extract your numbers. However, if there are any significant number of multiple matches, you can run the script again with some print statements to show you example filenames that provoke a multiple match. This would tell you whether or not a simple adjustment to the regex might work.
For instance, if you have 23,768 multiple matches on T-numbers, then make the script print every 500th filename with multiple matches, which would give you 47 samples to examine.
Probably something like [ -/.=]T[0-9]+[ -/.=] would be enough to get the multiple matches down to zero, while also giving a one-time match for every filename. Or at worst, [0-9][ -/.=]T[0-9]+[ -/.=]
For Python, see this question about TemplateMaker.