c ++读取csv文件

时间:2013-11-12 17:56:44

标签: c++ csv

我想用c ++读取csv文件 所以这是我的代码

 int main(){
 ifstream classFile("class.csv");
 vector<string> classData;

 while (getline(classFile, line,',')) // there is input overload classfile
        {
            classData.push_back(line);  

        }
}

这是我的问题:我的问题是它何时读取每一行的最后一列 (因为它没有用逗号分隔),它读取最后一列数据和下一行数据的第一列 例如,如果我的数据是

className,classLocation,教授 c ++,Library,John

然后它读起来像className / classLocation / Professor c ++ / Library / John

无论如何,我可以将我的最后一列与下一行的第一列分开吗? 谢谢,对不起,这令人困惑

3 个答案:

答案 0 :(得分:17)

逐行阅读文件:

std::string line;
while(std::getline(stream, line)) ...

将每一行传递给istingstream并阅读字段:

std::istringstream s(line);
std::string field;
while (getline(s, field,',')) ...

<强>声明: 这是对csv文件的简化解析。

答案 1 :(得分:3)

对不起,我可以将一些简单的C推入这个帖子吗?

在那里阅读csv非常清楚:

#include <stdio.h>


int main()
{
  float f1, f2;

  FILE *fp;
  fp = fopen("file.csv", "r");

  while (fscanf(fp, "%g,%g\n", &f1, &f2) == 2)
    printf("%g\n", f1+f2);
}

当然,它应该适用于C ++的工作原理。

while中,我们检查fscanf找到了多少个对象:fscanf(fp, "%g,%g\n", &f1, &f2) == 2 - fscanf返回它找到的对象数。

我希望它对某人有所帮助。

(如果有人希望在fscanf上查看更多信息并阅读文件 - 请留下一些评论。)

答案 2 :(得分:0)

如果您有兴趣在void部分中调用main函数,请查看以下代码:

void readCSV(const string &strPath2Dataset)
{   
    ifstream csvFile;
    string strPathCSVFile = strPath2Dataset + "/test.csv";
    csvFile.open(strPathCSVFile.c_str());

    if (!csvFile.is_open())
    {
        cout << "Path Wrong!!!!" << endl;
        exit(EXIT_FAILURE);
    }

    vector<long double> timeStampIMU;
    vector<long double> gyro_X;
    vector<long double> gyro_Y;
    vector<long double> gyro_Z;

    vector<long double> acc_X;
    vector<long double> acc_Y;
    vector<long double> acc_Z;

    string line;
    vector <string> vec;
    getline(csvFile, line); // skip the 1st line

    while (getline(csvFile,line))
    {
        if (line.empty()) // skip empty lines:
        {
            //cout << "empty line!" << endl;
            continue;
        }

        istringstream iss(line);
        string lineStream;
        string::size_type sz;

        vector <long double> row;

        while (getline(iss, lineStream, ','))
        {  
            row.push_back(stold(lineStream,&sz)); // convert to double
        }

        timeStampIMU.push_back(row[0]);

        gyro_X.push_back(row[1]);
        gyro_Y.push_back(row[2]);
        gyro_Z.push_back(row[3]);

        acc_X.push_back(row[4]);
        acc_Y.push_back(row[5]);
        acc_Z.push_back(row[6]);
    }

    //cout << "size ts = " << timeStampIMU.size() << endl;
    for (size_t i = 0; i < timeStampIMU.size(); i++)
    {
        cout << "ts_imu = " << setprecision(12) << timeStampIMU[i] << endl;

        cout << "gx = " << setprecision(12) << gyro_X[i] << endl;
        cout << "gy = " << setprecision(12) << gyro_Y[i] << endl;
        cout << "gz = " << setprecision(12) << gyro_Z[i] << endl;

        cout << "ax = " << setprecision(12) << acc_X[i] << endl;
        cout << "ay = " << setprecision(12) << acc_Y[i] << endl;
        cout << "az = " << setprecision(12) << acc_Z[i] << endl;
        cout << "--------------------------------" << endl;
    }
}

我的.csv文件是从IMU传感器提供的数据集,用逗号分隔:

TimeStamp, Gyro_X, Gyro_Y, Gyro_Z, Acc_X, Acc_Y, Acc_Z