CSV data manipulation
You are encouraged to solve this task according to the task description, using any language you may know.
CSV spreadsheet files are portable ways of storing tabular data. The CSV format is either flexible or ill defined, depending on a point of view, allowing for delimiters besides comma.
The task here is to read a CSV file, change some values and save the changes back to a file. For this task we will use the following CSV file:
C1,C2,C3,C4,C5 1,5,9,13,17 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20
AWK
adds a column sum to a csv table <lang AWK>#!/usr/bin/awk -f BEGIN { FS=",";} { if (NR==1) { print $0""FS"SUM"; } else { s = 0; for (k=1; k<=NF; k++) { s += $k; } print $0""FS""s; } }</lang>
awk -f csv_data_manipulation.awk data.csv C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
C++
<lang cpp>#include <map>
- include <vector>
- include <iostream>
- include <fstream>
- include <utility>
- include <functional>
- include <string>
- include <sstream>
- include <algorithm>
- include <cctype>
class CSV { public:
CSV(void) : m_nCols( 0 ), m_nRows( 0 )
{}
bool open( const char* filename, char delim = ',' )
{
std::ifstream file( filename );
clear();
if ( file.is_open() )
{
open( file, delim );
return true;
}
return false; }
void open( std::istream& istream, char delim = ',' )
{
std::string line;
clear();
while ( std::getline( istream, line ) )
{
unsigned int nCol = 0;
std::istringstream lineStream(line);
std::string cell;
while( std::getline( lineStream, cell, delim ) )
{
m_oData[std::make_pair( nCol, m_nRows )] = trim( cell );
nCol++;
}
m_nCols = std::max( m_nCols, nCol );
m_nRows++;
}
}
bool save( const char* pFile, char delim = ',' )
{
std::ofstream ofile( pFile );
if ( ofile.is_open() )
{
save( ofile );
return true;
}
return false;
}
void save( std::ostream& ostream, char delim = ',' )
{
for ( unsigned int nRow = 0; nRow < m_nRows; nRow++ )
{
for ( unsigned int nCol = 0; nCol < m_nCols; nCol++ )
{
ostream << trim( m_oData[std::make_pair( nCol, nRow )] );
if ( (nCol+1) < m_nCols )
{
ostream << delim;
}
else
{
ostream << std::endl;
}
}
}
}
void clear()
{
m_oData.clear();
m_nRows = m_nCols = 0;
}
std::string& operator()( unsigned int nCol, unsigned int nRow )
{
m_nCols = std::max( m_nCols, nCol+1 );
m_nRows = std::max( m_nRows, nRow+1 );
return m_oData[std::make_pair(nCol, nRow)];
}
inline unsigned int GetRows() { return m_nRows; }
inline unsigned int GetCols() { return m_nCols; }
private:
// trim string for empty spaces in begining and at the end
inline std::string &trim(std::string &s)
{
s.erase(s.begin(), std::find_if(s.begin(), s.end(), std::not1(std::ptr_fun<int, int>(std::isspace))));
s.erase(std::find_if(s.rbegin(), s.rend(), std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
return s;
}
private:
std::map<std::pair<unsigned int, unsigned int>, std::string> m_oData;
unsigned int m_nCols; unsigned int m_nRows;
};
int main()
{
CSV oCSV;
oCSV.open( "test_in.csv" ); oCSV( 0, 0 ) = "Column0"; oCSV( 1, 1 ) = "100"; oCSV( 2, 2 ) = "200"; oCSV( 3, 3 ) = "300"; oCSV( 4, 4 ) = "400"; oCSV.save( "test_out.csv" ); return 0;
}</lang>
- Output (in test_out.csv):
Column0,C2,C3,C4,C5 1,100,9,13,17 2,6,200,14,18 3,7,11,300,19 4,8,12,16,400
C#
<lang csharp>using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO;
namespace CSV {
class CSV
{
private Dictionary<Tuple<int, int>, string> _data;
private int _rows;
private int _cols;
public int Rows { get { return _rows; } }
public int Cols { get { return _cols; } }
public CSV()
{
Clear();
}
public void Clear()
{
_rows = 0;
_cols = 0;
_data = new Dictionary<Tuple<int, int>, string>();
}
public void Open(StreamReader stream, char delim = ',')
{
string line;
int col = 0;
int row = 0;
Clear();
while ((line = stream.ReadLine()) != null)
{
if (line.Length > 0)
{
string[] values = line.Split(delim);
col = 0;
foreach (var value in values)
{
this[col,row] = value;
col++;
}
row++;
}
}
stream.Close();
}
public void Save(StreamWriter stream, char delim = ',')
{
for (int row = 0; row < _rows; row++)
{
for (int col = 0; col < _cols; col++)
{
stream.Write(this[col, row]);
if (col < _cols - 1)
{
stream.Write(delim);
}
}
stream.WriteLine();
}
stream.Flush();
stream.Close();
}
public string this[int col, int row]
{
get
{
try
{
return _data[new Tuple<int, int>(col, row)];
}
catch
{
return "";
}
}
set
{
_data[new Tuple<int, int>(col, row)] = value.ToString().Trim();
_rows = Math.Max(_rows, row + 1);
_cols = Math.Max(_cols, col + 1);
}
}
static void Main(string[] args)
{
CSV csv = new CSV();
csv.Open(new StreamReader(@"test_in.csv"));
csv[0, 0] = "Column0";
csv[1, 1] = "100";
csv[2, 2] = "200";
csv[3, 3] = "300";
csv[4, 4] = "400";
csv.Save(new StreamWriter(@"test_out.csv"));
}
}
}</lang>
- Output (in test_out.csv):
Column0,C2,C3,C4,C5 1,100,9,13,17 2,6,200,14,18 3,7,11,300,19 4,8,12,16,400
Erlang
<lang Erlang> -module( csv_data ).
-export( [change/2, from_binary/1, from_file/1, into_file/2, task/0] ).
change( CSV, Changes ) -> lists:foldl( fun change_foldl/2, CSV, Changes ).
from_binary( Binary ) ->
Lines = binary:split( Binary, <<"\n">>, [global] ),
[binary:split(X, <<",">>, [global]) || X <- Lines].
from_file( Name ) ->
{ok, Binary} = file:read_file( Name ),
from_binary( Binary ).
into_file( Name, CSV ) ->
Binaries = join_binaries( [join_binaries(X, <<",">>) || X <- CSV], <<"\n">> ),
file:write_file( Name, Binaries ).
task() ->
CSV = from_file( "CSV_file.in" ),
New_CSV = change( CSV, [{2,3,<<"23">>}, {4,4,<<"44">>}] ),
into_file( "CSV_file.out", New_CSV ).
change_foldl( {Row_number, Column_number, New}, Acc ) ->
{Row_befores, [Row_columns | Row_afters]} = split( Row_number, Acc ),
{Column_befores, [_Old | Column_afters]} = split( Column_number, Row_columns ),
Row_befores ++ [Column_befores ++ [New | Column_afters]] ++ Row_afters.
join_binaries( Binaries, Binary ) ->
[_Last | Rest] = lists:reverse( lists:flatten([[X, Binary] || X <- Binaries]) ),
lists:reverse( Rest ).
split( 1, List ) -> {[], List}; split( N, List ) -> lists:split( N - 1, List ). </lang>
- Output:
Contents of "CSV_file.out"
C1,C2,C3,C4,C5 1,5,23,13,17 2,6,10,14,18 3,7,11,44,19 4,8,12,16,20
F#
<lang fsharp>open System open System.Collections.Generic open System.IO
type Csv = class
val private _data : Dictionary<int * int, string> val mutable private _rows : int val mutable private _cols : int
new () =
{ _data = new Dictionary<int * int, string>();
_rows = 0; _cols = 0 }
member this.Rows with get () = this._rows
member this.Cols with get () = this._cols
member this.Item
with get(row,col) =
match this._data.TryGetValue((row,col)) with
| (true, s) -> s | _ -> ""
and set(row,col) value =
this._data.[(row,col)] <- value
this._rows <- Math.Max(this._rows, row + 1)
this._cols <- Math.Max(this._cols, col + 1)
member this.Open(stream : StreamReader, delim : char) =
this._data.Clear()
this._cols <- 0
this._rows <- 0
Seq.unfold (
fun (s : StreamReader) -> if s.EndOfStream then None else Some(s.ReadLine(), s)) stream
|> Seq.iteri (
fun i line ->
line.Split(delim)
|> Array.iteri (fun j item -> this.[i,j] <- item))
stream.Close()
member this.Open(stream : StreamReader) =
this.Open(stream, ',')
member this.Save(writer : TextWriter, delim : char) =
for row = 0 to this._rows - 1 do
String.Join(delim.ToString(),
[0 .. this._cols - 1]
|> List.map(fun col -> this.[row,col])
|> List.toArray)
|> writer.WriteLine
member this.Save(writer : TextWriter) =
this.Save(writer, ',')
end
[<EntryPoint>]
let main argv =
let csv = new Csv() csv.Open(new StreamReader(argv.[0])) csv.[0, 0] <- "Column0" csv.[1, 1] <- "100" csv.[2, 2] <- "200" csv.[3, 3] <- "300" csv.[4, 4] <- "400" csv.Save(Console.Out) 0</lang>
- Output:
>Rosetta.exe test_in.csv Column0,C2,C3,C4,C5 1,100,9,13,17 2,6,200,14,18 3,7,11,300,19 4,8,12,16,400
Go
<lang go>package main
import ( "encoding/csv" "io" "log" "os" "strconv" )
func init() { log.SetFlags(log.Lshortfile) }
func main() { // Open the sample file given. csvFile, err := os.Open("sample.csv")
// Exit on error. if err != nil { log.Fatal("Error opening sample csv file:", err) }
// Make sure the file is closed before the function returns. defer csvFile.Close()
// Create a new csv reader for the file. csvReader := csv.NewReader(csvFile)
// Create an output file. outputFile, err := os.Create("output.csv") if err != nil { log.Fatal("Error creating output file:", err) } defer outputFile.Close()
csvWriter := csv.NewWriter(outputFile) defer csvWriter.Flush()
// For each row in the data. for i := 0; ; i++ { record, err := csvReader.Read() if err == io.EOF { break } if err != nil { log.Fatal("Error reading record:", err) }
// Skip header row. if i == 0 { err = csvWriter.Write(record) if err != nil { log.Fatal("Error writing record to output file:", err) } continue }
// For each cell in the row. for cell := range record { // Convert value to integer for manipulation. v, err := strconv.Atoi(record[cell]) if err != nil { log.Fatal("Error parsing cell value:", err) }
// Do something to the value. v += 1 // Store the new value back in the record variable. record[cell] = strconv.Itoa(v) }
// Write modified record to disk. err = csvWriter.Write(record) if err != nil { log.Fatal("Error writing record to output file:", err) } } }</lang> <lang>C1,C2,C3,C4,C5 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20 5,9,13,17,21</lang>
Haskell
<lang haskell>import Data.Array import Data.Maybe (isJust) import Data.List (intercalate) import Control.Monad (when)
delimiters = ",;:"
fields [] = [] fields xs = let (item, rest) = break (`elem` delimiters) xs
(_, next) = break (`notElem` delimiters) rest in item : fields next
unfields Nothing = [] unfields (Just a) = every fieldNumber $ elems a
where
((_, _), (_, fieldNumber)) = bounds a
every _ [] = []
every n xs = let (y, z) = splitAt n xs
in intercalate "," y : every n z
fieldArray [] = Nothing fieldArray xs = Just $ listArray ((1,1), (length xs, length $ head xs))
$ concat xs
fieldsFromFile = fmap (fieldArray . map fields . lines) . readFile
fieldsToFile f = writeFile f . unlines . unfields
someChanges = fmap (// [((1,1), "changed"), ((3,4), "altered"),
((5,2), "modified")])
main = do
a <- fieldsFromFile "example.txt" when (isJust a) $ fieldsToFile "output.txt" $ someChanges a
</lang>
Icon and Unicon
This version only works in Unicon, but can be easily adapted to work in Icon.
<lang unicon>import Utils # To get CSV procedures
procedure main(A)
f := open(A[1]) | &input
i := 1
write(!f) # header line(?)
every csv := parseCSV(!f) do {
csv[i+:=1] *:= 100
write(encodeCSV(csv))
}
end</lang>
Sample run:
->csv csv.dat C1,C2,C3,C4,C5 1,500,9,13,17 2,6,1000,14,18 3,7,11,1500,19 4,8,12,16,2000 ->
Java
<lang java>import java.io.*; import java.awt.Point; import java.util.HashMap; import java.util.Scanner;
public class CSV {
private HashMap<Point, String> _map = new HashMap<Point, String>(); private int _cols; private int _rows;
public void open(File file) throws FileNotFoundException, IOException {
open(file, ',');
}
public void open(File file, char delimiter)
throws FileNotFoundException, IOException {
Scanner scanner = new Scanner(file);
scanner.useDelimiter(Character.toString(delimiter));
clear();
while(scanner.hasNextLine()) {
String[] values = scanner.nextLine().split(Character.toString(delimiter));
int col = 0;
for ( String value: values ) {
_map.put(new Point(col, _rows), value);
_cols = Math.max(_cols, ++col);
}
_rows++;
}
scanner.close();
}
public void save(File file) throws IOException {
save(file, ',');
}
public void save(File file, char delimiter) throws IOException {
FileWriter fw = new FileWriter(file);
BufferedWriter bw = new BufferedWriter(fw);
for (int row = 0; row < _rows; row++) {
for (int col = 0; col < _cols; col++) {
Point key = new Point(col, row);
if (_map.containsKey(key)) {
bw.write(_map.get(key));
}
if ((col + 1) < _cols) {
bw.write(delimiter);
}
}
bw.newLine();
}
bw.flush();
bw.close();
}
public String get(int col, int row) {
String val = "";
Point key = new Point(col, row);
if (_map.containsKey(key)) {
val = _map.get(key);
}
return val;
}
public void put(int col, int row, String value) {
_map.put(new Point(col, row), value);
_cols = Math.max(_cols, col+1);
_rows = Math.max(_rows, row+1);
}
public void clear() {
_map.clear();
_cols = 0;
_rows = 0;
}
public int rows() {
return _rows;
}
public int cols() {
return _cols;
}
public static void main(String[] args) {
try {
CSV csv = new CSV();
csv.open(new File("test_in.csv"));
csv.put(0, 0, "Column0");
csv.put(1, 1, "100");
csv.put(2, 2, "200");
csv.put(3, 3, "300");
csv.put(4, 4, "400");
csv.save(new File("test_out.csv"));
} catch (Exception e) {
}
}
}</lang>
- Output (in test_out.csv):
Column0,C2,C3,C4,C5 1,100,9,13,17 2,6,200,14,18 3,7,11,300,19 4,8,12,16,400
Mathematica
Mathematica's Import and Export functions support CSV files. <lang mathematica>iCSV=Import["test.csv"] ->{{"C1","C2","C3","C4","C5"},{1,5,9,13,17},{2,6,10,14,18},{3,7,11,15,19},{4,8,12,16,20}} iCSV1, 1 = Column0; iCSV2, 2 = 100; iCSV3, 3 = 200; iCSV4, 4 = 300; iCSV5, 5 = 400; iCSV2, 3 = 60; Export["test.csv",iCSV];</lang>
- Output:
Column0,C2,C3,C4,C5 1,100,60,13,17 2,6,200,14,18 3,7,11,300,19 4,8,12,16,400
MATLAB / Octave
<lang Matlab>filename='data.csv'; fid = fopen(filename); header = fgetl(fid); fclose(fid); X = dlmread(filename,',',1,0);
fid = fopen('data.out.csv','w+'); fprintf(fid,'%s,sum\n',header); for k=1:size(X,1), fprintf(fid,"%i,",X(k,:)); fprintf(fid,"%i\n",sum(X(k,:))); end; fclose(fid);</lang>
Perl
For simple files, you can use split: <lang perl>#!/usr/bin/perl use warnings; use strict;
use List::Util 'sum';
my @header = split /,/, <>;
- Remove the newline.
chomp $header[-1];
my %column_number; for my $i (0 .. $#header) {
$column_number{$header[$i]} = $i;
} my @rows = map [ split /,/ ], <>; chomp $_->[-1] for @rows;
- Add 1 to the numbers in the 2nd column:
$_->[1]++ for @rows;
- Add C1 into C4:
$_->[ $column_number{C4} ] += $_->[ $column_number{C1} ] for @rows;
- Add sums to both rows and columns.
push @header, 'Sum'; $column_number{Sum} = $#header;
push $_, sum(@$_) for @rows; push @rows, [
map {
my $col = $_;
sum(map $_->[ $column_number{$col} ], @rows);
} @header
];
- Print the output.
print join(',' => @header), "\n"; print join(',' => @$_), "\n" for @rows; </lang>
However, if the CSV can contain quoted texts (the type MS Excel produces), you should rather use the Text::CSV. Only reading the data and printing the result is different: <lang perl>#!/usr/bin/perl use warnings; use strict;
use Text::CSV; use List::Util 'sum';
my $csv = 'Text::CSV'->new({eol => "\n"})
or die 'Cannot use CSV: ' . 'Text::CSV'->error_diag;
my $file = shift; my @rows; open my $FH, '<', $file or die "Cannot open $file: $!"; my @header = @{ $csv->getline($FH) }; while (my $row = $csv->getline($FH)) {
push @rows, $row;
} $csv->eof or $csv->error_diag;
- The processing is the same.
- Print the output.
$csv->print(*STDOUT, $_) for \@header, @rows;</lang>
Perl 6
On the face of it this task is pretty simple. Especially given the sample CSV file and the total lack of specification of what changes to make to the file. Something like this would suffice. <lang perl6>my $csvfile = './whatever.csv'; my $fh = open($csvfile, :r); my @header = $fh.get.split(','); my @csv = map {[.split(',')]}, $fh.lines; close $fh;
my $out = open($csvfile, :w); $out.say((@header,'SUM').join(',')); $out.say((@$_, [+] @$_).join(',')) for @csv; close $out;</lang> But if your CSV file is at all complex you are better off using a CSV parsing module. (Complex meaning fields that contain commas, quotes, newlines, etc.) <lang perl6>use Text::CSV; my $csvfile = './whatever.csv'; my @csv = Text::CSV.parse-file($file); modify(@csv); # do whatever; csv-write-file( @csv, :file($csvfile) );</lang>
PicoLisp
<lang PicoLisp>(in "data.csv"
(prinl (line) "," "SUM")
(while (split (line) ",")
(prinl (glue "," @) "," (sum format @)) ) )</lang>
Output:
C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
PL/I
<lang pli>*process source xref attributes or(!);
csv: Proc Options(Main); /********************************************************************* * 19.10.2013 Walter Pachl * 'erase d:\csv.out' * 'set dd:in=d:\csv.in,recsize(300)' * 'set dd:out=d:\csv.out,recsize(300)' * Say 'Input:' * 'type csv.in' * 'csv' * Say ' ' * Say 'Output:' * 'type csv.out' *********************************************************************/ Dcl in Record Input; Dcl out Record Output; On Endfile(in) Goto part2; Dcl (INDEX,LEFT,SUBSTR,TRIM) Builtin;
Dcl (i,j,p,m,n) Bin Fixed(31) Init(0); Dcl s Char(100) Var; Dcl iline(10) Char(100) Var; Dcl a(20,20) Char(10) Var; Dcl sum Dec Fixed(3); Dcl oline Char(100) Var;
Do i=1 By 1; Read File(in) Into(s); iline(i)=s; m=i; Call sep((s)); End;
part2:
Do i=1 To m;
If i=1 Then
oline=iline(1)!!','!!'SUM';
Else Do;
sum=0;
Do j=1 To n;
sum=sum+a(i,j);
End;
oline=iline(i)!!','!!trim(sum);
End;
Write File(out) From(oline);
End;
sep: Procedure(line);
Dcl line Char(*) Var;
loop:
Do j=1 By 1;
p=index(line,',');
If p>0 Then Do;
a(i,j)=left(line,p-1);
line=substr(line,p+1);
End;
Else Do;
a(i,j)=line;
Leave loop;
End;
End;
n=j;
End;
End;</lang>
Output:
Input: C1,C2,C3,C4,C5 1,5,9,13,17 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20 Output: C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
Python
Note that the csv module is not required for such a simple and regular csv file. <lang python>import fileinput
changerow, changecolumn, changevalue = 2, 4, '"Spam"'
with fileinput.input('csv_data_manipulation.csv', inplace=True) as f:
for line in f:
if fileinput.filelineno() == changerow:
fields = line.rstrip().split(',')
fields[changecolumn-1] = changevalue
line = ','.join(fields) + '\n'
print(line, end=)</lang>
- Output:
After this the data file csv_data_manipulation.csv gets changed from that of the task to:
C1,C2,C3,C4,C5 1,5,9,"Spam",17 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20
Racket
<lang racket>#lang racket (require (planet neil/csv:1:=7) net/url)
(define make-reader
(make-csv-reader-maker
'((separator-chars #\,)
(strip-leading-whitespace? . #t)
(strip-trailing-whitespace? . #t))))
(define (all-rows port)
(define read-row (make-reader port))
(define head (append (read-row) '("SUM")))
(define rows (for/list ([row (in-producer read-row '())])
(define xs (map string->number row))
(append row (list (~a (apply + xs))))))
(define (->string row) (string-join row "," #:after-last "\n"))
(string-append* (map ->string (cons head rows))))</lang>
Example: <lang racket>(define csv-file
"C1, C2, C3, C4, C5 1, 5, 9, 13, 17 2, 6, 10, 14, 18 3, 7, 11, 15, 19 4, 8, 12, 16, 20")
(display (all-rows (open-input-string csv-file)))</lang>
- Output:
C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
REXX
<lang rexx>/* REXX ***************************************************************
- extend in.csv to add a column containing the sum of the lines' elems
- 21.06.2013 Walter Pachl
- /
csv='in.csv' Do i=1 By 1 While lines(csv)>0
l=linein(csv)
If i=1 Then
l.i=l',SUM'
Else Do
ol=l
sum=0
Do While l<>
Parse Var l e ',' l
sum=sum+e
End
l.i=ol','sum
End
End
Call lineout csv 'erase' csv Do i=1 To i-1
Call lineout csv,l.i End</lang>
- Output:
C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
Ruby
<lang ruby>require 'csv'
- read:
ar = CSV.table("test.csv").to_a #table method assumes headers and converts numbers if possible.
- manipulate:
ar.first << "SUM" ar[1..-1].each{|row| row << row.inject(:+)}
- write:
CSV.open("out.csv", 'w') do |csv|
ar.each{|line| csv << line}
end</lang>
- Output:
c1,c2,c3,c4,c5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
Run BASIC
<lang runbasic>csv$ = "C1,C2,C3,C4,C5 1,5,9,13,17 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20 "
print csv$ dim csvData$(5,5)
for r = 1 to 5
a$ = word$(csv$,r,chr$(13)) for c = 1 to 5 csvData$(r,c) = word$(a$,c,",") next c
next r
[loop] input "Row to change:";r input "Col to change;";c if r > 5 or c > 5 then
print "Row ";r;" or Col ";c;" is greater than 5" goto [loop]
end if input "Change Row ";r;" Col ";c;" from ";csvData$(r,c);" to ";d$ csvData$(r,c) = d$ for r = 1 to 5
for c = 1 to 5 print cma$;csvData$(r,c); cma$ = "," next c cma$ = "" print
next r</lang>
C1,C2,C3,C4,C5 1,5,9,13,17 2,6,10,14,18 3,7,11,15,19 4,8,12,16,20 Row to change:?4 Col to change;?4 Change Row 4 Col 4 from 15 to ?99 C1,C2,C3,C4,C5 1,5,9,13,17 2,6,10,14,18 3,7,11,99,19 4,8,12,16,20
Tcl
<lang tcl>package require struct::matrix package require csv
proc addSumColumn {filename {title "SUM"}} {
set m [struct::matrix]
# Load the CSV in set f [open $filename] csv::read2matrix $f $m "," auto close $f
# Add the column with the sums
set sumcol [$m columns]
$m add column $title
for {set i 1} {$i < [$m rows]} {incr i} {
# Fill out a dummy value $m set cell $sumcol $i 0 $m set cell $sumcol $i [tcl::mathop::+ {*}[$m get row $i]]
}
# Write the CSV out set f [open $filename w] csv::writematrix $m $f close $f
$m destroy
}
addSumColumn "example.csv"</lang>
- Output (in example.csv):
C1,C2,C3,C4,C5,SUM 1,5,9,13,17,45 2,6,10,14,18,50 3,7,11,15,19,55 4,8,12,16,20,60
Vedit macro language
This example adds 100 to the values in each cell at row n+1, column n. <lang vedit>File_Open("input.csv") for (#1 = 0; #1 < 4; #1++) {
Goto_Line(#1+2) // line (starting from line 2)
if (#1) {
Search(",", ADVANCE+COUNT, #1) // column
}
#2 = Num_Eval() // #2 = old value
Del_Char(Chars_Matched) // delete old value
Num_Ins(#2+100, LEFT+NOCR) // write new value
} File_Save_As("output.csv", OK+NOMSG) </lang> output.csv:
C1,C2,C3,C4,C5 101,5,9,13,17 2,106,10,14,18 3,7,111,15,19 4,8,12,116,20