SparseDtype

class pandas::SparseDtype

Data type class for pandas extension types.

Example

#include <pandas/pandas.h>
using namespace pandas;

// Use SparseDtype
SparseDtype obj;
// ... operations ...

Arithmetic

Signature	Return Type	Location	Example
std::string subtype_name() const	std::string	pd_sparse_dtype.h:156

Iteration

Signature	Return Type	Location	Example
size_t itemsize() const override	size_t	pd_sparse_dtype.h:132

Type Checking

Signature	Return Type	Location	Example
bool is_default_fill_value() const	bool	pd_sparse_dtype.h:196

Other Methods

Signature	Return Type	Location	Example
static T default_fill_value()	static T	pd_sparse_dtype.h:80
T fill_value() const	T	pd_sparse_dtype.h:148	View
SparseDtype() : fill_value_(default_fill_value())	SparseDtype() :	pd_sparse_dtype.h:66
explicit SparseDtype(T fill_value) : fill_value_(fill_value)	explicit SparseDtype(T fill_value) :	pd_sparse_dtype.h:72
std::string kind() const override	std::string	pd_sparse_dtype.h:140	View
std::string name() const override	std::string	pd_sparse_dtype.h:101	View
numpy::DType numpy_dtype() const override	numpy::DType	pd_sparse_dtype.h:125
std::string repr() const override	std::string	pd_sparse_dtype.h:189	View
void set_fill_value_display(const std::string& display)	void	pd_sparse_dtype.h:95
void set_subtype_name(const std::string& name)	void	pd_sparse_dtype.h:93
const std::type_info& type() const override	const std::type_info&	pd_sparse_dtype.h:163	View

Code Examples

The following examples are extracted from the test suite.

fill_value (pd_test_1_all.cpp:3229)

        std::cout << " -> tests passed" << std::endl;
    }

    void pd_test_sparse_array_fill_value_property() {
        std::cout << "========= SparseArray: fill_value property ======================= ";

        std::vector<numpy::int64> data = {-1, 5, -1, 10, -1};
        pandas::SparseArray<numpy::int64> arr(data, static_cast<numpy::int64>(-1));

        if (arr.fill_value() != -1) {
            std::cout << "  [FAIL] : in pd_test_sparse_array_fill_value_property() : fill_value != -1" << std::endl;
            throw std::runtime_error("pd_test_sparse_array_fill_value_property failed: fill_value != -1");
        }

        // Test default fill_value for float (NaN)
        pandas::SparseArray<numpy::float64> arr_float;
        if (!std::isnan(arr_float.fill_value())) {
            std::cout << "  [FAIL] : in pd_test_sparse_array_fill_value_property() : default float fill_value should be NaN" << std::endl;
            throw std::runtime_error("pd_test_sparse_array_fill_value_property failed: default float fill_value should be NaN");
        }

kind (pd_test_1_all.cpp:300)

    void pd_test_boolean_array_dtype() {
        std::cout << "========= BooleanArray: dtype ======================= ";

        pandas::BooleanArray arr;
        if (arr.dtype().name() != "boolean") {
            std::cout << "  [FAIL] : in pd_test_boolean_array_dtype() : dtype name should be 'boolean'" << std::endl;
            throw std::runtime_error("pd_test_boolean_array_dtype failed: dtype name");
        }

        if (arr.dtype().kind() != "b") {
            std::cout << "  [FAIL] : in pd_test_boolean_array_dtype() : dtype kind should be 'b'" << std::endl;
            throw std::runtime_error("pd_test_boolean_array_dtype failed: dtype kind");
        }

        std::cout << " -> tests passed" << std::endl;
    }
}

int pd_test_boolean_array_main() {
    std::cout << "====================================== running pd_test_boolean_array ==================================== " << std::endl;

name (pd_test_1_all.cpp:295)

            throw std::runtime_error("pd_test_boolean_array_reductions failed: mean");
        }

        std::cout << " -> tests passed" << std::endl;
    }

    void pd_test_boolean_array_dtype() {
        std::cout << "========= BooleanArray: dtype ======================= ";

        pandas::BooleanArray arr;
        if (arr.dtype().name() != "boolean") {
            std::cout << "  [FAIL] : in pd_test_boolean_array_dtype() : dtype name should be 'boolean'" << std::endl;
            throw std::runtime_error("pd_test_boolean_array_dtype failed: dtype name");
        }

        if (arr.dtype().kind() != "b") {
            std::cout << "  [FAIL] : in pd_test_boolean_array_dtype() : dtype kind should be 'b'" << std::endl;
            throw std::runtime_error("pd_test_boolean_array_dtype failed: dtype kind");
        }

        std::cout << " -> tests passed" << std::endl;

repr (pd_test_1_all.cpp:10906)

    std::cout << " -> tests passed" << std::endl;
}

void pd_test_extension_index_repr() {
    std::cout << "========= repr =========================";

    pandas::CategoricalArray arr({"a", "b", "c"});
    // Use ExtensionIndex<CategoricalArray> directly to test base class repr
    pandas::ExtensionIndex<pandas::CategoricalArray> idx(arr, "test");

    std::string repr_str = idx.repr();

    bool passed = (!repr_str.empty() && repr_str.find("ExtensionIndex") != std::string::npos);
    if (!passed) {
        std::cout << "  [FAIL] : in pd_test_extension_index_repr() : repr check failed" << std::endl;
        throw std::runtime_error("pd_test_extension_index_repr failed");
    }

    std::cout << " -> tests passed" << std::endl;
}

type (pd_test_3_all.cpp:15450)

/**
 * Test Series.convert_dtypes() parameter flags
 */
void pd_test_series_convert_dtypes_flags() {
    std::cout << "========= Series.convert_dtypes() flags =================";

    // Test convert_integer=false - with floats disabled too, so it becomes string/object
    pandas::Series<std::string> s({"1", "2", "3"}, "numbers");
    auto converted = s.convert_dtypes(true, true, false, true, false);  // convert_integer=false, convert_floating=false

    // Should remain object type (Series<std::string> has dtype_name()="object")
    // When integer and floating are both disabled for integer-like strings, it falls back to string type
    if (converted->dtype_name() != "object") {
        std::cout << "  [FAIL] : dtype should be object when convert_integer=false and convert_floating=false, got " << converted->dtype_name() << std::endl;
        throw std::runtime_error("pd_test_series_convert_dtypes_flags failed: convert_integer");
    }

    // Test convert_boolean=false - strings stay as object/string type
    pandas::Series<std::string> s_bool({"true", "false"}, "bools");
    auto converted_bool = s_bool.convert_dtypes(true, true, true, false, true);  // convert_boolean=false