StructuredDType

class numpy::StructuredDType

numpy C++ class.

Example

#include <numpy/np_ndarray.h>
using namespace numpy;

// Use StructuredDType
StructuredDType obj;
// ... operations ...

Constructors

Signature	Location	Example
StructuredDType(const std::vector<std::pair<std::string,DType>>&field_specs, boolpacked = false)	NP_STRUCTURED_DTYPE.H:104
StructuredDType(const std::vector<FieldDescriptor>&fields, boolpacked = false)	NP_STRUCTURED_DTYPE.H:117

Indexing / Selection

Signature	Return Type	Location	Example
size_t getAlignment()	size_t	NP_STRUCTURED_DTYPE.H:148
const FieldDescriptor & getField(const std::string &name)	const FieldDescriptor &	NP_STRUCTURED_DTYPE.H:127	View
const FieldDescriptor & getField(size_tindex)	const FieldDescriptor &	NP_STRUCTURED_DTYPE.H:135	View
size_t getFieldAlignment(DTypedtype)	size_t	NP_STRUCTURED_DTYPE.H:90
size_t getFieldCount()	size_t	NP_STRUCTURED_DTYPE.H:146	View
size_t getFieldIndex(const std::string &name)	size_t	NP_STRUCTURED_DTYPE.H:160
const std::vector<FieldDescriptor>& getFields()	const std::vector<FieldDescriptor>&	NP_STRUCTURED_DTYPE.H:125
size_t getTotalSize()	size_t	NP_STRUCTURED_DTYPE.H:147

Other Methods

Signature	Return Type	Location	Example
void calculateLayout()	void	NP_STRUCTURED_DTYPE.H:65
std::string dtypeToString(DTypedtype)	std::string	NP_STRUCTURED_DTYPE.H:190
bool hasField(const std::string &name)	bool	NP_STRUCTURED_DTYPE.H:142	View
bool isPacked()	bool	NP_STRUCTURED_DTYPE.H:149
std::string toString()	std::string	NP_STRUCTURED_DTYPE.H:168	View

Code Examples

The following examples are extracted from the test suite.

getField (np_test_2_all.cpp:18700)

    void np_test_io_extensions_recfromcsv_dtype_detection() {
      std::cout << "========= recfromcsv: automatic dtype detection =======================";

      create_csv_file("test_dtypes.csv");

      auto data = numpy::io::recfromcsv(csv_test_dir + "test_dtypes.csv");
      auto dtype = data.getDType();

      // Verify string field detected
      auto name_dtype = dtype.getField("name").dtype;
      if (name_dtype != numpy::DType::STR32 && name_dtype != numpy::DType::STR16 &&
        name_dtype != numpy::DType::STR8 && name_dtype != numpy::DType::STR64) {
        std::cout << "  [FAIL] : Expected STRING type for name field" << std::endl;
        throw std::runtime_error("np_test_io_extensions_recfromcsv_dtype_detection failed: wrong name dtype");
      }

      // Verify integer field detected
      auto age_dtype = dtype.getField("age").dtype;
      if (age_dtype != numpy::DType::INT64 && age_dtype != numpy::DType::INT32) {
        std::cout << "  [FAIL] : Expected INT type for age field";

getField (np_test_2_all.cpp:18700)

    void np_test_io_extensions_recfromcsv_dtype_detection() {
      std::cout << "========= recfromcsv: automatic dtype detection =======================";

      create_csv_file("test_dtypes.csv");

      auto data = numpy::io::recfromcsv(csv_test_dir + "test_dtypes.csv");
      auto dtype = data.getDType();

      // Verify string field detected
      auto name_dtype = dtype.getField("name").dtype;
      if (name_dtype != numpy::DType::STR32 && name_dtype != numpy::DType::STR16 &&
        name_dtype != numpy::DType::STR8 && name_dtype != numpy::DType::STR64) {
        std::cout << "  [FAIL] : Expected STRING type for name field" << std::endl;
        throw std::runtime_error("np_test_io_extensions_recfromcsv_dtype_detection failed: wrong name dtype");
      }

      // Verify integer field detected
      auto age_dtype = dtype.getField("age").dtype;
      if (age_dtype != numpy::DType::INT64 && age_dtype != numpy::DType::INT32) {
        std::cout << "  [FAIL] : Expected INT type for age field";

getFieldCount (np_test_2_all.cpp:18627)

      // Verify shape
      if (data.getShape()[0] != 3) {
        std::cout << "  [FAIL] : in np_test_io_extensions_recfromcsv_basic() : Expected 3 rows, got "
          << data.getShape()[0] << std::endl;
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: wrong row count");
      }

      // Verify field count
      auto dtype = data.getDType();
      if (dtype.getFieldCount() != 5) {
        std::cout << "  [FAIL] : in np_test_io_extensions_recfromcsv_basic() : Expected 5 fields, got "
          << dtype.getFieldCount() << std::endl;
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: wrong field count");
      }

      // Verify field names
      if (!dtype.hasField("name") || !dtype.hasField("age") || !dtype.hasField("salary")) {
        std::cout << "  [FAIL] : in np_test_io_extensions_recfromcsv_basic() : Missing expected fields";
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: missing fields");
      }

hasField (np_test_2_all.cpp:18634)

      // Verify field count
      auto dtype = data.getDType();
      if (dtype.getFieldCount() != 5) {
        std::cout << "  [FAIL] : in np_test_io_extensions_recfromcsv_basic() : Expected 5 fields, got "
          << dtype.getFieldCount() << std::endl;
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: wrong field count");
      }

      // Verify field names
      if (!dtype.hasField("name") || !dtype.hasField("age") || !dtype.hasField("salary")) {
        std::cout << "  [FAIL] : in np_test_io_extensions_recfromcsv_basic() : Missing expected fields";
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: missing fields");
      }

      // Verify data values
      auto name = data.getFieldValue<numpy::str32>({ 0 }, "name");
      if (std::string(name) != "Alice") {
        std::cout << "  [FAIL] : Expected 'Alice', got '" << std::string(name) << "'";
        throw std::runtime_error("np_test_io_extensions_recfromcsv_basic failed: wrong name");
      }

toString (np_test_1_all.cpp:6826)

void testDatetime64CreationDateTime() {
    std::cout << "========= testDatetime64CreationDateTime =======================";

    // Test default constructor
    datetime64 default_dt;
    if (!(default_dt.isNaT())) {
        std::string description = std::string("testDatetime64CreationDateTime():") + __FILE__ + ":" + std::to_string(__LINE__) + ": !(default_dt.isNaT())";
        std::cout << std::string("[FAIL] ") + description << std::endl;
        throw std::runtime_error(description);
    }
    // std::cout << "Default datetime64 is NaT: " << default_dt.toString() << std::endl;

    // Test value constructor
    datetime64 epoch_day(0, DateTimeUnit::Day);
    // std::cout << "Epoch day: " << epoch_day.toString() << std::endl;

    // Test string constructor
    datetime64 date_from_string("2024-01-15");
    // std::cout << "Date from string '2024-01-15': " << date_from_string.toString() << std::endl;

    datetime64 datetime_from_string("2024-01-15T10:30:45");