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Parsing a CSV file separated by semicolons.

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Join Date: Oct 2007

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Duoas

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Re: Parsing a CSV file separated by semicolons.

#11

Jul 21st, 2009

Sorry to respond to this late... but I wanted to post info also...

The getline() function has the obnoxious habit of returning a not good() stream for final blank fields...

For a single blank line at the end of input, that's fine... (there's no record) but for blank fields it makes a difference. You can get past the problem by checking the stream state before getting a line.

For simple CSV files (meaning you cannot use the ';' character [or whatever character you've chosen] in the field value) this is a working example:

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 C++ Syntax (Toggle Plain Text) 
#include <deque>
#include <iostream>
#include <sstream>
#include <string>
 
typedef std::deque <std::string> record_t;
typedef std::deque <record_t>    table_t;
 
std::istream& operator >> ( std::istream& ins, table_t& table )
  {
  std::string s;
  table.clear();
 
  while (std::getline( ins, s ))
    {
    std::istringstream ss( s );
    record_t           record;
    std::string        field;
    bool               final = true;
 
    while (std::getline( ss, field, ';' ))
      {
      record.push_back( field );
      final = ss.eof();
      }
    if (!final)
      record.push_back( std::string() );
 
    table.push_back( record );
    }
 
  return ins;
  }
#include <deque>
#include <iostream>
#include <sstream>
#include <string>

typedef std::deque <std::string> record_t;
typedef std::deque <record_t>    table_t;

std::istream& operator >> ( std::istream& ins, table_t& table )
  {
  std::string s;
  table.clear();

  while (std::getline( ins, s ))
    {
    std::istringstream ss( s );
    record_t           record;
    std::string        field;
    bool               final = true;

    while (std::getline( ss, field, ';' ))
      {
      record.push_back( field );
      final = ss.eof();
      }
    if (!final)
      record.push_back( std::string() );

    table.push_back( record );
    }

  return ins;
  }

This will allow you to read all seven fields in a record like:

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one; two;three;four;;six;

Hope this helps.

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Join Date: Sep 2008

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Yaserk88

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Re: Parsing a CSV file separated by semicolons.

#12

Jul 23rd, 2009

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Originally Posted by Ancient Dragon

The only problem with your program is that you need to set local for the stringstream object.
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    while (getline(infile, line))
	{
        stringstream strstr(line);
        string word = "";
	    strstr.imbue(locale("german_germany.1252"));
        while (getline(strstr,word, ';')) 
            all_words.push_back(word);
    }
while (getline(infile, line)) { stringstream strstr(line); string word = ""; strstr.imbue(locale("german_germany.1252")); while (getline(strstr,word, ';')) all_words.push_back(word); }
Attached is the output file I got.

Hi Ancient Dragon. I see that this makes sense, but the commas in the numbers are not being replaced with decimals. I think the reason for this is that things are still in strings and I need to convert them to integer and float values.

For instances when I do all_words[0] + all_words[2] (all_words[0]=2 and all_words[2]=31), I get 231.

How do I convert each indviudal value of my file so that I can specify it either as int, float, or string?

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Join Date: Sep 2008

Posts: 24

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Yaserk88

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Re: Parsing a CSV file separated by semicolons.

#13

Jul 23rd, 2009

I will actually mark this thread as solved and post it as a different problem, because it may be useful for other people. Thanks for the help everyone!