CSV data source

Class csv::data_source is an API for accessing the data source represented as a csv file. CSV data source shall be used with read operation to extract data in text format from the given input file, process it using provided parameters (such as delimiter and read options), transform it into numerical representation, and store it as an in-memory dataset of a chosen type.

Supported type of in-memory object for read operation with CSV data source is oneapi::dal::table.

CSV data source requires input file name to be set in the constructor, while the other parameters of the constructor such as delimiter and read options rely on default values.

Usage example

using namespace oneapi;

const auto data_source = dal::csv::data_source("data.csv", ',');

const auto table = dal::read<dal::table>(data_source);

Programming Interface

All types and functions in this section shall be declared in the oneapi::dal::csv namespace and be available via inclusion of the oneapi/dal/io/csv.hpp header file.

enum class read_options : std::uint64_t {
   none = 0,
   parse_header = 1 << 0
};

constexpr char default_delimiter = ',';
constexpr read_options default_read_options = read_options::none;

class data_source {
public:
   data_source(const char *file_name,
               char delimiter = default_delimiter,
               read_options opts = default_read_options);

   data_source(const std::string &file_name,
               char delimiter = default_delimiter,
               read_options opts = default_read_options);

   std::string get_file_name() const;
   char get_delimiter() const;
   read_options get_read_options() const;
};

class data_source

data_source(const char *file_name, char delimiter = default_delimiter, read_options opts = default_read_options)

Creates a new instance of a CSV data source with the given file_name, delimiter and read options opts flag.

data_source(const std::string &file_name, char delimiter = default_delimiter, read_options opts = default_read_options)

Creates a new instance of a CSV data source with the given file_name, delimiter and read options opts flag.

std::string file_name = ""

A string that contains the name of the file with the dataset to read.

Getter

std::string get_filename() const

char delimiter = default_delimiter

A character that represents the delimiter between separate features in the input file.

Getter

char get_delimter() const

read_options options = default_read_options

Value that stores read options to be applied during reading of the input file. Enabled parse_header option indicates that the first line in the input file shall be processed as a header record with features names.

Getter

read_options get_read_options() const

Reading oneapi::dal::read<Object>(...)

Args

template <typename Object>
class read_args {
public:
   read_args();
};

template<typename Object>
class read_args

read_args()

Creates args for the read operation with the default attribute values.

Operation

oneapi::dal::table is the only supported value of the Object template parameter for read operation with CSV data source.

template<typename Object, typename DataSource>
Object read(const DataSource &ds)

Template Parameters:

• Object – oneDAL object type that shall be produced as a result of reading from the data source.

• DataSource – CSV data source csv::data_source.