Attrs
=====

.. cpp:class:: pandas::Attrs

   Utility class for pandas operations.

Example
-------

.. code-block:: cpp

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

   // Use Attrs
   Attrs obj;
   // ... operations ...

Constructors
------------

.. list-table::
   :widths: 55 25 20
   :header-rows: 1

   * - Signature
     - Location
     - Example
   * - ``Attrs() = default``
     - pd_attrs.h:52
     - 
   * - ``Attrs(const Attrs&) = default``
     - pd_attrs.h:57
     - 
   * - ``Attrs(Attrs&&) = default``
     - pd_attrs.h:62
     - 

Indexing / Selection
--------------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``T get(const std::string& key) const``
     - T
     - pd_attrs.h:103
     - :ref:`View <example-attrs-get-0>`
   * - ``T get(const std::string& key, T default_value) const``
     - T
     - pd_attrs.h:119
     - :ref:`View <example-attrs-get-1>`

Combining
---------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``void merge(const Attrs& other, bool overwrite = true)``
     - void
     - pd_attrs.h:217
     - :ref:`View <example-attrs-merge-2>`

Conversion
----------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``Attrs copy() const``
     - Attrs
     - pd_attrs.h:229
     - :ref:`View <example-attrs-copy-3>`

Iteration
---------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``std::vector<std::string> keys() const``
     - std::vector<std::string>
     - pd_attrs.h:188
     - :ref:`View <example-attrs-keys-4>`

Other Methods
-------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``void clear()``
     - void
     - pd_attrs.h:164
     - :ref:`View <example-attrs-clear-5>`
   * - ``bool contains(const std::string& key) const``
     - bool
     - pd_attrs.h:79
     - :ref:`View <example-attrs-contains-6>`
   * - ``bool empty() const``
     - bool
     - pd_attrs.h:180
     - :ref:`View <example-attrs-empty-7>`
   * - ``bool has_type(const std::string& key) const``
     - bool
     - pd_attrs.h:204
     - :ref:`View <example-attrs-has_type-8>`
   * - ``bool remove(const std::string& key)``
     - bool
     - pd_attrs.h:157
     - :ref:`View <example-attrs-remove-9>`
   * - ``void set(const std::string& key, T&& value)``
     - void
     - pd_attrs.h:90
     - :ref:`View <example-attrs-set-10>`
   * - ``size_t size() const``
     - size_t
     - pd_attrs.h:172
     - :ref:`View <example-attrs-size-11>`
   * - ``bool try_get(const std::string& key, T& out_value) const``
     - bool
     - pd_attrs.h:139
     - 


Code Examples
-------------

The following examples are extracted from the test suite.

.. _example-attrs-get-0:

.. dropdown:: get (pd_test_1_all.cpp:10290)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10280
      :emphasize-lines: 11

      void pd_test_extension_index_get_loc_unique() {
          std::cout << "========= get_loc (unique) =========================";
      
          pandas::CategoricalArray arr({"apple", "banana", "cherry"});
          pandas::CategoricalIndex idx(arr);
      
          auto loc_apple = idx.get_loc("apple");
          auto loc_banana = idx.get_loc("banana");
          auto loc_cherry = idx.get_loc("cherry");
      
          bool passed = (std::holds_alternative<size_t>(loc_apple) && std::get<size_t>(loc_apple) == 0 &&
                         std::get<size_t>(loc_banana) == 1 &&
                         std::get<size_t>(loc_cherry) == 2);
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_extension_index_get_loc_unique() : get_loc check failed" << std::endl;
              throw std::runtime_error("pd_test_extension_index_get_loc_unique failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }
      

.. _example-attrs-get-1:

.. dropdown:: get (pd_test_1_all.cpp:10290)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10280
      :emphasize-lines: 11

      void pd_test_extension_index_get_loc_unique() {
          std::cout << "========= get_loc (unique) =========================";
      
          pandas::CategoricalArray arr({"apple", "banana", "cherry"});
          pandas::CategoricalIndex idx(arr);
      
          auto loc_apple = idx.get_loc("apple");
          auto loc_banana = idx.get_loc("banana");
          auto loc_cherry = idx.get_loc("cherry");
      
          bool passed = (std::holds_alternative<size_t>(loc_apple) && std::get<size_t>(loc_apple) == 0 &&
                         std::get<size_t>(loc_banana) == 1 &&
                         std::get<size_t>(loc_cherry) == 2);
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_extension_index_get_loc_unique() : get_loc check failed" << std::endl;
              throw std::runtime_error("pd_test_extension_index_get_loc_unique failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }
      

.. _example-attrs-merge-2:

.. dropdown:: merge (pd_test_1_all.cpp:13639)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 13629
      :emphasize-lines: 11

      namespace dataframe_tests {
          namespace dataframe_tests_joining {
      
              // Helper to check approximate equality
              bool approx_equal(double a, double b, double tol = 1e-9) {
                  if (std::isnan(a) && std::isnan(b)) return true;
                  return std::abs(a - b) < tol;
              }
      
              // =====================================================================
              // merge() Tests
              // =====================================================================
      
              void pd_test_joining_merge_inner() {
                  std::cout << "========= merge inner join ============================";
      
                  // Left DataFrame: id, value_left
                  std::map<std::string, std::vector<double>> left_data = {
                      {"id", {1.0, 2.0, 3.0, 4.0}},
                      {"value_left", {10.0, 20.0, 30.0, 40.0}}
                  };

.. _example-attrs-copy-3:

.. dropdown:: copy (pd_test_1_all.cpp:5798)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 5788
      :emphasize-lines: 11

      // ============================================================================
      // Copy/Rename Tests
      // ============================================================================
      
      void pd_test_categorical_index_copy() {
          std::cout << "========= copy ========================================";
      
          pandas::CategoricalArray arr({"a", "b", "c"});
          pandas::CategoricalIndex idx(arr, "original");
      
          pandas::CategoricalIndex copied = idx.copy();
      
          bool passed = (copied.size() == idx.size() && copied.name() == idx.name() &&
                         copied.categories() == idx.categories() && copied.ordered() == idx.ordered());
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_categorical_index_copy()" << std::endl;
              throw std::runtime_error("pd_test_categorical_index_copy failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }

.. _example-attrs-keys-4:

.. dropdown:: keys (pd_test_1_all.cpp:16319)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 16309
      :emphasize-lines: 11

                  }
      
                  // Test default value
                  passed = attrs.get<int>("missing", 99) == 99;
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : default value" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: default value");
                  }
      
                  // Test keys
                  auto keys = attrs.keys();
                  passed = keys.size() == 3;
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : keys()" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: keys()");
                  }
      
                  // Test remove
                  passed = attrs.remove("count") && !attrs.contains("count");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : remove" << std::endl;

.. _example-attrs-clear-5:

.. dropdown:: clear (pd_test_1_all.cpp:16341)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 16331
      :emphasize-lines: 11

                  }
      
                  // Test has_type
                  passed = attrs.has_type<std::string>("author") && !attrs.has_type<int>("author");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : has_type" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: has_type");
                  }
      
                  // Test clear
                  attrs.clear();
                  passed = attrs.empty();
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : clear" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: clear");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      
              // =====================================================================

.. _example-attrs-contains-6:

.. dropdown:: contains (pd_test_1_all.cpp:2200)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 2190
      :emphasize-lines: 11

      // Test: contains method
      // ============================================================================
      void test_contains() {
          std::cout << "========= IntervalArray: contains ======================= ";
      
          std::vector<numpy::float64> breaks = {0.0, 1.0, 2.0, 3.0};
      
          // Right-closed intervals: (0, 1], (1, 2], (2, 3]
          auto arr_right = pandas::IntervalArrayFloat64::from_breaks(breaks, pandas::IntervalClosed::Right);
      
          // Test contains(1.0) - should be in interval 0 but not 1 (since 1 is exclusive on left of interval 1)
          auto contains_1 = arr_right.contains(1.0);
          // (0, 1] contains 1: yes, (1, 2] contains 1: no (open on left), (2, 3] contains 1: no
          if (contains_1[0].value_or(false) != true ||
              contains_1[1].value_or(true) != false ||
              contains_1[2].value_or(true) != false) {
              std::cout << "[FAIL] : in test_contains() : right-closed contains 1.0" << std::endl;
              return;
          }
      
          // Left-closed intervals: [0, 1), [1, 2), [2, 3)

.. _example-attrs-empty-7:

.. dropdown:: empty (pd_test_1_all.cpp:941)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 931
      :emphasize-lines: 11

      
      #include "../pandas/pd_config.h"
      
      namespace dataframe_tests {
      
      namespace dataframe_tests_config {
      
          void pd_test_config_version() {
              std::cout << "========= df_config: version info ======================= ";
              const char* version = pandas::DataFrameInfo::version();
              if (version == nullptr || std::string(version).empty()) {
                  std::cout << "[FAIL] : in pd_test_config_version() : version is null or empty" << std::endl;
                  throw std::runtime_error("pd_test_config_version failed: version is null or empty");
              }
              std::cout << "-> tests passed" << std::endl;
          }
      
          void pd_test_config_na_repr() {
              std::cout << "========= df_config: NA representation ======================= ";
              const char* na_repr = pandas::DataFrameConfig::get_na_repr();
              if (na_repr == nullptr) {

.. _example-attrs-has_type-8:

.. dropdown:: has_type (pd_test_1_all.cpp:16334)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 16324
      :emphasize-lines: 11

                  }
      
                  // Test remove
                  passed = attrs.remove("count") && !attrs.contains("count");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : remove" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: remove");
                  }
      
                  // Test has_type
                  passed = attrs.has_type<std::string>("author") && !attrs.has_type<int>("author");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : has_type" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: has_type");
                  }
      
                  // Test clear
                  attrs.clear();
                  passed = attrs.empty();
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : clear" << std::endl;

.. _example-attrs-remove-9:

.. dropdown:: remove (pd_test_1_all.cpp:16327)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 16317
      :emphasize-lines: 11

      
                  // Test keys
                  auto keys = attrs.keys();
                  passed = keys.size() == 3;
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : keys()" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: keys()");
                  }
      
                  // Test remove
                  passed = attrs.remove("count") && !attrs.contains("count");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : remove" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: remove");
                  }
      
                  // Test has_type
                  passed = attrs.has_type<std::string>("author") && !attrs.has_type<int>("author");
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : has_type" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: has_type");

.. _example-attrs-set-10:

.. dropdown:: set (pd_test_1_all.cpp:16281)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 16271
      :emphasize-lines: 11

                  pandas::Attrs attrs;
      
                  // Test empty
                  bool passed = attrs.empty() && attrs.size() == 0;
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : empty attrs" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: empty attrs");
                  }
      
                  // Test set/get string
                  attrs.set("author", std::string("John Doe"));
                  passed = attrs.contains("author") && attrs.get<std::string>("author") == "John Doe";
                  if (!passed) {
                      std::cout << "  [FAIL] : in pd_test_ndframe_attrs() : set/get string" << std::endl;
                      throw std::runtime_error("pd_test_ndframe_attrs failed: set/get string");
                  }
      
                  // Test set/get double
                  attrs.set("version", 1.5);
                  passed = std::abs(attrs.get<double>("version") - 1.5) < 1e-10;
                  if (!passed) {

.. _example-attrs-size-11:

.. dropdown:: size (pd_test_1_all.cpp:22)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 12
      :emphasize-lines: 11

      #include "../pandas/pd_boolean_array.h"
      
      namespace dataframe_tests {
      
      namespace dataframe_tests_boolean_array {
          void pd_test_boolean_array_constructors() {
              std::cout << "========= BooleanArray: constructors ======================= ";
      
              // Default constructor
              pandas::BooleanArray arr1;
              if (arr1.size() != 0) {
                  std::cout << "  [FAIL] : in pd_test_boolean_array_constructors() : default constructor size != 0" << std::endl;
                  throw std::runtime_error("pd_test_boolean_array_constructors failed: default constructor size != 0");
              }
      
              // Initializer list constructor
              pandas::BooleanArray arr2({
                  std::optional<bool>(true),
                  std::optional<bool>(false),
                  std::nullopt,
                  std::optional<bool>(true)