#include <csv2/reader.hpp> int main() { csv2::Reader<csv2::delimiter<','>, csv2::quote_character<'"'>, csv2::first_row_is_header<true>, csv2::trim_policy::trim_whitespace> csv; if (csv.mmap("foo.csv")) { const auto header = csv.header(); for (const auto row: csv) { for (const auto cell: row) { // Do something with cell value // std::string value; // cell.read_value(value); } } } }This benchmark measures the average execution time (of 5 runs after 3 warmup runs) for csv2 to memory-map the input CSV file and iterate over every cell in the CSV. See benchmark/main.cpp for more details.
cd benchmark g++ -I../include -O3 -std=c++11 -o main main.cpp ./main <csv_file>| Type | Value |
|---|---|
| Processor | 11th Gen Intel(R) Core(TM) i9-11900KF @ 3.50GHz 3.50 GHz |
| Installed RAM | 32.0 GB (31.9 GB usable) |
| SSD | ADATA SX8200PNP |
| OS | Ubuntu 20.04 LTS running on WSL in Windows 11 |
| C++ Compiler | g++ (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0 |
| Dataset | File Size | Rows | Cols | Time |
|---|---|---|---|---|
| Denver Crime Data | 111 MB | 479,100 | 19 | 0.102s |
| AirBnb Paris Listings | 196 MB | 141,730 | 96 | 0.170s |
| 2015 Flight Delays and Cancellations | 574 MB | 5,819,079 | 31 | 0.603s |
| StackLite: Stack Overflow questions | 870 MB | 17,203,824 | 7 | 0.911s |
| Used Cars Dataset | 1.4 GB | 539,768 | 25 | 0.947s |
| Title-Based Semantic Subject Indexing | 3.7 GB | 12,834,026 | 4 | 2.867s |
| Bitcoin tweets - 16M tweets | 4 GB | 47,478,748 | 9 | 3.290s |
| DDoS Balanced Dataset | 6.3 GB | 12,794,627 | 85 | 6.963s |
| Seattle Checkouts by Title | 7.1 GB | 34,892,623 | 11 | 7.698s |
| SHA-1 password hash dump | 11 GB | 2,62,974,241 | 2 | 10.775s |
| DOHUI NOH scaled_data | 16 GB | 496,782 | 3213 | 16.553s |
Here is the public API available to you:
template <class delimiter = delimiter<','>, class quote_character = quote_character<'"'>, class first_row_is_header = first_row_is_header<true>, class trim_policy = trim_policy::trim_whitespace> class Reader { public: // Use this if you'd like to mmap and read from file bool mmap(string_type filename); // Use this if you have the CSV contents in std::string already bool parse(string_type contents); // Shape size_t rows() const; size_t cols() const; // Row iterator // If first_row_is_header, row iteration will start // from the second row RowIterator begin() const; RowIterator end() const; // Access the first row of the CSV Row header() const; };Here's the Row class:
// Row class class Row { public: // Get raw contents of the row void read_raw_value(Container& value) const; // Cell iterator CellIterator begin() const; CellIterator end() const; };and here's the Cell class:
// Cell class class Cell { public: // Get raw contents of the cell void read_raw_value(Container& value) const; // Get converted contents of the cell // Handles escaped content, e.g., // """foo""" => ""foo"" void read_value(Container& value) const; };This library also provides a basic csv2::Writer class - one that can be used to write CSV rows to file. Here's a basic usage:
#include <csv2/writer.hpp> #include <vector> #include <string> using namespace csv2; int main() { std::ofstream stream("foo.csv"); Writer<delimiter<','>> writer(stream); std::vector<std::vector<std::string>> rows = { {"a", "b", "c"}, {"1", "2", "3"}, {"4", "5", "6"} }; writer.write_rows(rows); stream.close(); }Here is the public API available to you:
template <class delimiter = delimiter<','>> class Writer { public: // Construct using an std::ofstream Writer(output_file_stream stream); // Use this to write a single row to file void write_row(container_of_strings row); // Use this to write a list of rows to file void write_rows(container_of_rows rows);mkdir build && cd build cmake -DCSV2_BUILD_TESTS=ON .. make cd test ./csv2_testpython3 utils/amalgamate/amalgamate.py -c single_include.json -s .Contributions are welcome, have a look at the CONTRIBUTING.md document for more information.
The project is available under the MIT license.