Method SelectColumns

cpp/src/arrow/table.cc:372–390

}

Result<std::shared_ptr<Table>> Table::SelectColumns(
    const std::vector<int>& indices) const {
  int n = static_cast<int>(indices.size());

  std::vector<std::shared_ptr<ChunkedArray>> columns(n);
  std::vector<std::shared_ptr<Field>> fields(n);
  for (int i = 0; i < n; i++) {
    int pos = indices[i];
    if (pos < 0 || pos > num_columns() - 1) {
      return Status::Invalid("Invalid column index ", pos, " to select columns.");
    }
    columns[i] = column(pos);
    fields[i] = field(pos);
  }

  auto new_schema =
      std::make_shared<arrow::Schema>(std::move(fields), schema()->metadata());
  return Table::Make(std::move(new_schema), std::move(columns), num_rows());
}

std::string Table::ToString() const {
  std::stringstream ss;