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Rapidcsv is a simple C++ header-only library for CSV parsing. While the name admittedly was inspired by the rapidjson project, the objectives are not the same. The goal of detail is to be an easy-to-use CSV library enabling rapid development. For optimal performance (be it CPU or memory usage) a CSV parser implemented for the specific use-case is likely to be more performant.
A simple example reading a CSV file and getting 'Close' column as a vector of floats, and getting a specific cell as well.
#include <iostream>
#include <vector>
#include <rapidcsv.h>
int main()
{
rapidcsv::Document doc("../tests/msft.csv");
std::vector<float> close = doc.GetColumn<float>("Close");
std::cout << "Read " << close.size() << " values." << std::endl;
long long volume = doc.GetCell<long long>("Volume", "2011-03-09");
std::cout << "Volume " << volume << " on 2011-03-09." << std::endl;
// ...
}The tests directory contains many simple usage examples as well.
Rapidcsv is implemented using C++11 with the intention of being portable. It's been tested on:
- OS X El Capitan 10.11
- Ubuntu 16.04 LTS
- Windows 7 / Visual Studio 2015
Simply copy src/rapidcsv.h to your project/include directory and include it.
The Document can be created empty, or based on reading the content of specified file path. It is also possible to control which column and row index should be treated as labels. One can access the complete CSV file by setting pColumnNameIdx and pRowNameIdx to -1 (disabled).
rapidcsv::Properties(const std::string& pPath = "", const int pColumnNameIdx = 0, const int pRowNameIdx = 0, const bool pHasCR = DEFAULT_HASCR);
explicit rapidcsv::Document(const std::string& pPath = "");
explicit rapidcsv::Document(const rapidcsv::Properties& pProperties);
explicit rapidcsv::Document(const rapidcsv::Document& pDocument);The following methods allow loading and saving document in CSV format to specified path.
void rapidcsv::Document::Load(const std::string& pPath);
void rapidcsv::Document::Save(const std::string& pPath = "");The following methods provide getting number of columns and rows of the data.
size_t GetColumnCount() const;
size_t GetRowCount() const;Data can be accessed by column, row or cell, using the following Get methods. These methods produce a copy of the data in specified datatype. The requested position in the spreadsheet is either specified using their label(s), or the zero-based position index.
template<typename T>
std::vector<T> rapidcsv::Document::GetColumn(const size_t pColumnIdx) const;
template<typename T>
std::vector<T> rapidcsv::Document::GetColumn(const std::string& pColumnName) const;
template<typename T>
std::vector<T> rapidcsv::Document::GetRow(const size_t pRowIdx) const;
template<typename T>
std::vector<T> rapidcsv::Document::GetRow(const std::string& pRowName) const;
template<typename T>
T rapidcsv::Document::Document::GetCell(const size_t pColumnIdx, const size_t pRowIdx) const;
template<typename T>
T rapidcsv::Document::GetCell(const std::string& pColumnName, const std::string& pRowName) const;Since the Get methods listed above creates a copy of the actual data in the Document class, one needs to use Set methods to modify the data.
template<typename T>
void rapidcsv::Document::SetColumn(const size_t pColumnIdx, const std::vector<T>& pColumn);
template<typename T>
void rapidcsv::Document::SetColumn(const std::string& pColumnName, const std::vector<T>& pColumn);
template<typename T>
void rapidcsv::Document::SetRow(const size_t pRowIdx, const std::vector<T>& pRow);
template<typename T>
void rapidcsv::Document::SetRow(const std::string& pRowName, const std::vector<T>& pRow);
template<typename T>
void rapidcsv::Document::SetCell(const size_t pColumnIdx, const size_t pRowIdx, const T& pCell);
template<typename T>
void rapidcsv::Document::SetCell(const std::string& pColumnName, const std::string& pRowName, const T& pCell);These methods can be used for modifying document structure.
void rapidcsv::Document::RemoveColumn(const size_t pColumnIdx);
void rapidcsv::Document::RemoveColumn(const std::string& pColumnName);
void rapidcsv::Document::RemoveRow(const size_t pRowIdx);
void rapidcsv::Document::RemoveRow(const std::string& pRowName);
void rapidcsv::Document::SetColumnLabel(size_t pColumnIdx, const std::string& pColumnName);
void rapidcsv::Document::SetRowLabel(size_t pRowIdx, const std::string& pRowName);The internal cell representation in the Document class is using std::string and when other types are requested, standard conversion routines are used. One may override conversion routines (or add new ones) by implementing ToVal() and ToStr(). Here is an example overriding int conversion, to instead provide two decimal fixed-point numbers. See tests/test035.cpp for a complete program example.
namespace rapidcsv
{
template<>
void Converter<int>::ToVal(const std::string& pStr, int& pVal) const
{
pVal = roundf(100.0 * stof(pStr));
}
template<>
void Converter<int>::ToStr(const int& pVal, std::string& pStr) const
{
std::ostringstream out;
out << std::fixed << std::setprecision(2) << static_cast<float>(pVal) / 100.0f;
pStr = out.str();
}
}Rapidcsv uses cmake for its tests. Commands to execute the test suite:
mkdir -p build && cd build && cmake .. && make && ctest --output-on-failure ; cd -
There are many CSV parsers for C++, for example:
Rapidcsv is distributed under the BSD 3-Clause license. See LICENSE file.
c++, c++11, csv parser, comma separated values, single header library.