Extracting certain rows from a CSV file in C++

问题

I would like to know how I can extract / skip certain rows where, for example, age == 32 or age == None from a CSV file in C++.

~~Does it make more sense to extract the desired information after I loaded the entire csv file (if memory is not a problem)?~~

EDIT: If possible, I would like to have a reading, printing and modification part.

If possible, I want to use only the STL. The content of my test csv file looks as follows:

*test.csv*

name;age;weight;height;test
Bla;32;1.2;4.3;True
Foo;43;2.2;5.3;False
Bar;None;3.8;2.4;True
Ufo;32;1.5;5.4;True

I load the test.csv file with the following C++ program that prints the file's content on the screen:

#include <iostream>
#include <vector>
#include <string>
#include <iomanip>
#include <fstream>
#include <sstream>

void readCSV(std::vector<std::vector<std::string> > &data, std::string filename);
void printCSV(const std::vector<std::vector<std::string>> &data);

int main(int argc, char** argv) {
    std::string file_path = "./test.csv";
    std::vector<std::vector<std::string> > data;
    readCSV(data, file_path);
    printCSV(data);
    return 0;
}

void readCSV(std::vector<std::vector<std::string> > &data, std::string filename) {
    char delimiter = ';';
    std::string line;
    std::string item;
    std::ifstream file(filename);
    while (std::getline(file, line)) {
        std::vector<std::string> row;
        std::stringstream string_stream(line);
        while (std::getline(string_stream, item, delimiter)) {
            row.push_back(item);
        }
        data.push_back(row);
    }
    file.close();
}

void printCSV(const std::vector<std::vector<std::string> > &data) {
    for (std::vector<std::string> row: data) {
        for (std::string item: row) {
            std::cout << item << ' ';
        }
        std::cout << std::endl;
    }
}

Any assistance you can provide would be greatly appreciated.

来源：https://stackoverflow.com/questions/61007296/extracting-certain-rows-from-a-csv-file-in-c

标签

c++

csv

data-manipulation