boost utility functions for dealing with files

boostutil.h

// utility functions for boost matrices/vectors

#include <fstream>

namespace ublas = boost::numeric::ublas;
using namespace std;

// create matrix:
// ublas::matrix<double> my_matrix(num_rows, num_columns);
// loadtxt("/path/to/file", my_matrix);
//
// then access values with my_matrix(1,3) for example

void loadtxt(string fname, ublas::matrix<double> & M)
{
  ifstream f (fname.c_str());
    
  if(!f.is_open())
  {
    cerr << "Error opening file " << fname << ". Exiting..." << endl;
    exit(EXIT_FAILURE);
  }

  for (unsigned int i = 0; i < M.size1(); i++)
    for (unsigned int j = 0; j < M.size2(); j++)
      f >> M(i,j);

  f.close(); 
}

void savetxt(string fname, ublas::matrix<double> & M)
{
  ofstream f (fname.c_str());

  if(!f.is_open())
  {
    cerr << "Error opening file " << fname << ". Exiting..." << endl;
    exit(EXIT_FAILURE);
  }

  for (unsigned int i = 0; i < M.size1(); i++)
  {
    for (unsigned int j = 0; j < M.size2(); j++)
    {
      f << M(i,j);
      if(j < M.size2()-1) f << " ";
      else f << endl;
    }
  }

  f.close(); 
}

hi sir
How to convert CSV to NetCDF using python. I have a script but something going wrong please help me?

from netCDF4 import Dataset
import numpy as np
import pandas as pd
import numpy as np
import numpy as np

from netCDF4 import Dataset

root = Dataset('fromTxt.nc','w',format='NETCDF4')

root.description = 'Example text input via numpy and netCDF4'

root.createDimension('Lon', None)

root.createDimension('Lat', None)

temp = root.createVariable('tem', 'f4', ('Lat','Lon',),fill_value=-9999)

#lats = np.arange(-90,90,0.2)
#lons = np.arange(-180,180,0.4)
#latitudes[:] = lats[:]
#langitudes[:] = lons[:]

f = open("ts_sept.csv")
a = pd.read_csv(f)

temp[:] = a[:]

root.close()