CSV

Abstract

csv2vvec()
Parsing CSV file to std::vector<std::vector<std::string>>.
CSV ファイルをパースして std::vector<std::vector<std::string>> に変換します.
vvec2csv()
Converting std::vector<std::vector<std::string>> to CSV file.
std::vector<std::vector<std::string>> を CSV ファイルに変換します.

Header file

namespace sstd{
    std::vector<std::vector<std::string>> csv2vvec(const        char* pReadFile);
    std::vector<std::vector<std::string>> csv2vvec(const std::string&  readFile);

    bool vvec2csv(const        char* pSavePath, const std::vector<std::vector<std::string>>& vecCSV);
    bool vvec2csv(const std::string&  savePath, const std::vector<std::vector<std::string>>& vecCSV);
}

Usage

csv2vvec()

example.csv
```
a, bcd
"hello, world", "efg"
```

main.cpp

#include <sstd/sstd.hpp>

int main(){
    std::vector<std::vector<std::string>> vv = sstd::csv2vvec("example.csv");
    sstd::printn( vv );
}

Execution result

vv = [["a" "bcd"] ["hello, world" "efg"]]

vvec2csv()

main.cpp

#include <sstd/sstd.hpp>

int main(){
    sstd::mkdir("./tmp");

    std::vector<std::vector<std::string>> vv = {{"a", "bcd"}, {"hello, world", "efg"}};
    sstd::vvec2csv("./tmp/example.csv", vv);

    printf("$ cat ./tmp/example.csv\n"); fflush(stdout); sstd::system("cat ./tmp/example.csv");

    sstd::rm("./tmp");
}

Execution result

$ cat ./tmp/example.csv
"a","bcd",
"hello, world","efg",

Appendix

CSV with header (string)

Below C++ code gets string CSV data removing header descriptions.
下記の C++ コードは，説明ヘッダを取り除いた文字列の CSV データを取得します．

CSV example

Range of Integers

Type name	Bytes	Range of values
int8_t	1	-128 ~ 127
int16_t	2	-32,768 ~ 32,767
int32_t	4	-2,147,483,648 ~ 2,147,483,647
int64_t	8	-9,223,372,036,854,775,808 ~ 9,223,372,036,854,775,807

main.cpp

#include <sstd/sstd.hpp>

int main(){
    sstd::mkdir("./tmp");
    {
        // write to CSV

        sstd::vvec<std::string> header = { // sstd::vvec<T> is same as a std::vector<std::vector<T>>.
            {"Type name", "Bytes", "Range of values"}
        };
        sstd::vvec<std::string> vvTable = {
            {"int8_t", "1", "-128 ~ 127"}, 
            {"int16_t", "2", "-32,768 ~ 32,767"}, 
            {"int32_t", "4", "-2,147,483,648 ~ 2,147,483,647"}, 
            {"int64_t", "8", "-9,223,372,036,854,775,808 ~ 9,223,372,036,854,775,807"}
        };
        sstd::vvec<std::string> vv = header << vvTable;
        sstd::vvec2csv("./tmp/example.csv", vv);
    }
    {
        // Read from CSV

        sstd::vvec<std::string> vvecOrig = sstd::csv2vvec("./tmp/example.csv");
        sstd::vvec<std::string> header   = vvecOrig && sstd::slice_mv(sstd::begin(), 1);
        sstd::vvec<std::string> vvS      = vvecOrig && sstd::slice_mv(1, sstd::end());
        sstd::printn(vvS);
    }
    sstd::rm("./tmp");
}

Execution result

vvS = [["int8_t" "1" "-128 ~ 127"] ["int16_t" "2" "-32,768 ~ 32,767"] ["int32_t" "4" "-2,147,483,648 ~ 2,147,483,647"] ["int64_t" "8" "-9,223,372,036,854,775,808 ~ 9,223,372,036,854,775,807"]]

CSV with header (double)

Below C++ code gets floating points CSV data removing header descriptions.
下記の C++ コードは，説明ヘッダを取り除いた浮動小数点数の CSV データを取得します．

CSV example

sin(Πx) and cos(Πx)

x	sin(πx)	cos(πx)
0.00	0.00	1.00
0.10	0.31	0.95
0.20	0.59	0.81
0.30	0.81	0.59
0.40	0.95	0.31
0.50	1.00	0.00
0.60	0.95	-0.31
0.70	0.81	-0.59
0.80	0.59	-0.81
0.90	0.31	-0.95
1.00	0.00	-1.00
1.10	-0.31	-0.95
1.20	-0.59	-0.81
1.30	-0.81	-0.59
1.40	-0.95	-0.31
1.50	-1.00	0.00
1.60	-0.95	0.31
1.70	-0.81	0.59
1.80	-0.59	0.81
1.90	-0.31	0.95
2.00	0.00	1.00

main.cpp

#include <sstd/sstd.hpp>

int main(){
    sstd::mkdir("./tmp");
    {
        // write to CSV

        sstd::vvec<std::string> header = { // sstd::vvec<T> is same as a std::vector<std::vector<T>>.
            {"x", "sin(πx)", "cos(πx)"}
        };
        std::vector<double> vX   = {0.00, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00};
        std::vector<double> vSin = {0.00, 0.31, 0.59, 0.81, 0.95, 1.00, 0.95, 0.81, 0.59, 0.31, 0.00, -0.31, -0.59, -0.81, -0.95, -1.00, -0.95, -0.81, -0.59, -0.31, 0.00};
        std::vector<double> vCos = {1.00, 0.95, 0.81, 0.59, 0.31, 0.00, -0.31, -0.59, -0.81, -0.95, -1.00, -0.95, -0.81, -0.59, -0.31, 0.00, 0.31, 0.59, 0.81, 0.95, 1.00};
        sstd::vvec<double> vvD = {{vX}, {vSin}, {vCos}};
        sstd::vvec<double> vvTable = sstd::Tr( vvD );
        /*
        // up is same as a below.
        sstd::vvec<double> vvTable = {
            {0.00,  0.00,  1.00},
            {0.10,  0.31,  0.95},
            {0.20,  0.59,  0.81},
            {0.30,  0.81,  0.59},
            {0.40,  0.95,  0.31},
            {0.50,  1.00,  0.00},
            {0.60,  0.95, -0.31}, 
            {0.70,  0.81, -0.59}, 
            {0.80,  0.59, -0.81}, 
            {0.90,  0.31, -0.95}, 
            {1.00,  0.00, -1.00}, 
            {1.10, -0.31, -0.95}, 
            {1.20, -0.59, -0.81}, 
            {1.30, -0.81, -0.59}, 
            {1.40, -0.95, -0.31}, 
            {1.50, -1.00,  0.00}, 
            {1.60, -0.95,  0.31}, 
            {1.70, -0.81,  0.59}, 
            {1.80, -0.59,  0.81}, 
            {1.90, -0.31,  0.95}, 
            {2.00,  0.00,  1.00}
        };*/
        sstd::vvec<std::string> vv = header << sstd::double2str(vvTable);
        sstd::vvec2csv("./tmp/example.csv", vv);
    }
    {
        // Read from CSV

        sstd::vvec<std::string> vvecOrig = sstd::csv2vvec("./tmp/example.csv");
        sstd::vvec<std::string> header   = vvecOrig && sstd::slice_mv(sstd::begin(), 1);
        sstd::vvec<std::string> vvS      = vvecOrig && sstd::slice_mv(1, sstd::end());
        sstd::vvec<     double> vvD      = sstd::Tr(sstd::str2double(vvS));
        sstd::printn(header);
        sstd::printn(vvD[0]);
        sstd::printn(vvD[1]);
        sstd::printn(vvD[2]);
    }
    sstd::rm("./tmp");
}

Execution result

header = [["x" "sin(πx)" "cos(πx)"]]
vvD[0] = [0. 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1. 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.]
vvD[1] = [0. 0.31 0.59 0.81 0.95 1. 0.95 0.81 0.59 0.31 0. -0.31 -0.59 -0.81 -0.95 -1. -0.95 -0.81 -0.59 -0.31 0.]
vvD[2] = [1. 0.95 0.81 0.59 0.31 0. -0.31 -0.59 -0.81 -0.95 -1. -0.95 -0.81 -0.59 -0.31 0. 0.31 0.59 0.81 0.95 1.]

Implementation

Source: sstd/src/file/csv.cpp
Header: sstd/src/file/csv.hpp
Test: test/src_test/file/csv.cpp (Not implemented yet)