Function mindspore::dataset::CSV

Function Documentation

inline std::shared_ptr<CSVDataset> mindspore::dataset::CSV(const std::vector<std::string> &dataset_files, char field_delim = ',', const std::vector<std::shared_ptr<CsvBase>> &column_defaults = {}, const std::vector<std::string> &column_names = {}, int64_t num_samples = 0, ShuffleMode shuffle = ShuffleMode::kGlobal, int32_t num_shards = 1, int32_t shard_id = 0, const std::shared_ptr<DatasetCache> &cache = nullptr)

Function to create a CSVDataset.

Note

The generated dataset has a variable number of columns.

Parameters

  • dataset_files – [in] List of files to be read to search for a pattern of files. The list will be sorted in a lexicographical order.

  • field_delim – [in] A char that indicates the delimiter to separate fields (default=’,’).

  • column_defaults – [in] List of default values for the CSV field (default={}). Each item in the list is either a valid type (float, int, or string). If this is not provided, treats all columns as string type.

  • column_names – [in] List of column names of the dataset (default={}). If this is not provided, infers the column_names from the first row of CSV file.

  • num_samples – [in] The number of samples to be included in the dataset. (Default = 0 means all samples).

  • shuffle – [in] The mode for shuffling data every epoch (Default=ShuffleMode::kGlobal). Can be any of: ShuffleMode::kFalse - No shuffling is performed. ShuffleMode::kFiles - Shuffle files only. ShuffleMode::kGlobal - Shuffle both the files and samples.

  • num_shards – [in] Number of shards that the dataset should be divided into. (Default = 1)

  • shard_id – [in] The shard ID within num_shards. This argument should be specified only when num_shards is also specified (Default = 0).

  • cache – [in] Tensor cache to use.(default=nullptr which means no cache is used).

Returns

Shared pointer to the CSVDataset

样例
/* Define dataset path and MindData object */
std::string train_file = "/path/to/csv_file";
std::vector<std::string> column_names = {"col1", "col2", "col3", "col4"};
std::shared_ptr<Dataset> ds = CSV({train_file}, ',', {}, column_names, 0, ShuffleMode::kFalse);

/* Create iterator to read dataset */
std::shared_ptr<Iterator> iter = ds->CreateIterator();
std::unordered_map<std::string, mindspore::MSTensor> row;
iter->GetNextRow(&row);

/* Note: As we defined before, the dataset has column "col1", "col2", "col3" and "col4" */
auto col1 = row["col1"];