csv.md

fast-cpp-csv-parser

Below is an example of how to use the fast-cpp-csv-parser to read a CSV file, allowing for ignoring missing or extra columns, and mapping the data into appropriate data types.

First, ensure you have the fast-cpp-csv-parser library. You can download it from its GitHub repository.

Here's the example code:

#include <iostream>
#include <string>
#include "csv.h"

// Define a structure to hold the data
struct Position {
    double x;
    double y;
    double z;
};

int main() {
    try {
        // Define the file path
        std::string filepath = "yourfile.csv";

        // Create a CSV reader with the specified columns
        io::CSVReader<3, io::trim_chars<' '>, io::double_quote_escape<',', '\"'>> in(filepath);
        in.read_header(io::ignore_missing_column | io::ignore_extra_column, "x", "y", "z");

        // Structure to hold the data
        Position position;

        // Read the rows and map the data to the structure
        while (in.read_row(position.x, position.y, position.z)) {
            // Process the data (for example, print it)
            std::cout << "x: " << position.x << ", y: " << position.y << ", z: " << position.z << std::endl;
        }
    } catch (const std::exception &e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}

Below is the modified code with additional exception handling for CSVError::FailedParse and other general exceptions:

#include <iostream>
#include <string>
#include "csv.h"

// Define a structure to hold the data
struct Position {
    double x;
    double y;
    double z;
};

int main() {
    try {
        // Define the file path
        std::string filepath = "yourfile.csv";

        // Create a CSV reader with the specified columns
        io::CSVReader<3, io::trim_chars<' '>, io::double_quote_escape<',', '\"'>> in(filepath);
        in.read_header(io::ignore_missing_column | io::ignore_extra_column, "x", "y", "z");

        // Structure to hold the data
        Position position;

        // Read the rows and map the data to the structure
        while (in.read_row(position.x, position.y, position.z)) {
            // Process the data (for example, print it)
            std::cout << "x: " << position.x << ", y: " << position.y << ", z: " << position.z << std::endl;
        }
    } catch (const io::error::can_not_open_file &e) {
        std::cerr << "Error: Can't open file. Reason: " << e.what() << std::endl;
    } catch (const io::error::base &e) {
        std::cerr << "Error: CSV parsing error. Reason: " << e.what() << std::endl;
    } catch (const std::exception &e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}

Explanation:

• We've added specific catch blocks for handling io::error::can_not_open_file and io::error::base, which are exceptions that can be thrown by the CSV library.
• io::error::can_not_open_file is thrown when the file cannot be opened, typically due to non-existence or insufficient permissions.
• io::error::base is a base class for other CSV parsing errors. We catch this to handle general CSV parsing errors.
• Other exceptions are caught by the catch block catch (const std::exception &e) to handle any unforeseen exceptions that might occur during file reading or processing.

Notes:

• Adjust the file path ("yourfile.csv") to point to the actual CSV file you want to parse.
• You may handle these exceptions differently based on your application's requirements. For example, you could log the errors or prompt the user to provide a valid file path.
• Make sure you have the necessary permissions to read the file specified.
• Compile the code using the same command provided in the previous response.

source