Question

我删除了我的旧帖子更精确。我正在使用c ++。我有一个csv;作为分隔符。使用以下代码我读了一行，然后我读取了行的所有元素并将它们转换为int。我的问题是我需要将它们转换为int16_t或int32_t。代码是：

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
using namespace std;

int main (int argc, const char * argv[]) {
    string line, csvItem;
    ifstream myfile ("modifica1.csv");
    int lineNumber = 0;
    int lineNumberSought = 7462;
    if (myfile.is_open()) {
        while (getline(myfile,line)) {
            lineNumber++;
            if(lineNumber == lineNumberSought) {
                istringstream myline(line);

        string bus1s;
        string bus2s;
        string bus3s;
        string bus4s;
        string bus5s;
        string bus6s;
        string bus7s;
        string bus8s;
        string bus9s;

        getline(myline,bus1s,';');
        getline(myline,bus2s,';');
        getline(myline,bus3s,';');
        getline(myline,bus4s,';');
        getline(myline,bus5s,';');
        getline(myline,bus6s,';');
        getline(myline,bus7s,';');
        getline(myline,bus8s,';');
        getline(myline,bus9s,'\n');


        int bus1;
        int bus2;
        int bus3;
        int bus4;
        int bus5;
        int bus6;
        int bus7;
        int bus8;
        int bus9;
        bus1=stoi(bus1s);
        bus2=stoi(bus2s);
        bus3=stoi(bus3s);
        bus4=stoi(bus4s);
        bus5=stoi(bus5s);
        bus6=stoi(bus6s);
        bus7=stoi(bus7s);
        bus8=stoi(bus8s);
        bus9=stoi(bus9s);

            }
        }
        myfile.close();
    }
    return 0;
}

Answer 1

以下是如何将csv文件（包含任何分隔符）解析为vector tuple的示例：

#include <sstream>
#include <vector>
#include <string>
#include <tuple>

#include <boost/lexical_cast.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/trim.hpp>

template<class... ColumnTypes>
class CsvRowParser
{
    char const separator_;

    template<size_t... Idxs>
    std::tuple<ColumnTypes...>
    convert_csv_row(std::vector<std::string> const& columns, std::integer_sequence<size_t, Idxs...>) {
        return std::tuple<ColumnTypes...>{boost::lexical_cast<ColumnTypes>(boost::algorithm::trim_copy(columns[Idxs]))...};
    }

public:
    using RowType = std::tuple<ColumnTypes...>;

    CsvRowParser(char separator)
        : separator_(separator)
    {}

    RowType parse_row(std::string const& csv_row) {
        std::vector<std::string> columns;
        boost::algorithm::split(columns, csv_row, [this](char c) { return c == separator_; });
        if(columns.size() != sizeof...(ColumnTypes))
            throw std::runtime_error("Invalid csv row: " + csv_row);
        return convert_csv_row(columns, std::make_index_sequence<sizeof...(ColumnTypes)>{});
    }
};

int main() {
    std::string my_csv;
    my_csv += "abc, 1, 1.1\n";
    my_csv += "def, 2, 2.2\n";
    std::istringstream s(my_csv);

    using Parser = CsvRowParser<std::string, int, double>;
    Parser parser(',');
    std::vector<Parser::RowType> rows;
    for(std::string line; getline(s, line);)
        rows.push_back(parser.parse_row(line));
}

转换为int16_t c ++

1 个答案: