PeriodDtype
===========

.. cpp:class:: pandas::PeriodDtype

   Data type class for pandas extension types.

Example
-------

.. code-block:: cpp

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

   // Use PeriodDtype
   PeriodDtype obj;
   // ... operations ...

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

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

   * - Signature
     - Location
     - Example
   * - ``explicit PeriodDtype(PeriodFrequency freq)``
     - pd_period_dtype.h:54
     - 
   * - ``explicit PeriodDtype(const std::string& freq_str)``
     - pd_period_dtype.h:62
     - 

Iteration
---------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``size_t itemsize() const override``
     - size_t
     - pd_period_dtype.h:87
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``PeriodFrequency freq() const``
     - PeriodFrequency
     - pd_period_dtype.h:109
     - :ref:`View <example-perioddtype-freq-0>`
   * - ``std::string freq_string() const``
     - std::string
     - pd_period_dtype.h:116
     - :ref:`View <example-perioddtype-freq_string-1>`
   * - ``std::string kind() const override``
     - std::string
     - pd_period_dtype.h:95
     - :ref:`View <example-perioddtype-kind-2>`
   * - ``bool matches(const std::string& dtype_name) const``
     - bool
     - pd_period_dtype.h:125
     - :ref:`View <example-perioddtype-matches-3>`
   * - ``std::string name() const override``
     - std::string
     - pd_period_dtype.h:72
     - :ref:`View <example-perioddtype-name-4>`
   * - ``numpy::DType numpy_dtype() const override``
     - numpy::DType
     - pd_period_dtype.h:80
     - 
   * - ``std::string repr() const override``
     - std::string
     - pd_period_dtype.h:136
     - :ref:`View <example-perioddtype-repr-5>`
   * - ``const std::type_info& type() const override``
     - const std::type_info&
     - pd_period_dtype.h:102
     - :ref:`View <example-perioddtype-type-6>`
   * - ``PeriodDtype with_freq(PeriodFrequency new_freq) const``
     - PeriodDtype
     - pd_period_dtype.h:143
     - 
   * - ``PeriodDtype with_freq(const std::string& new_freq) const``
     - PeriodDtype
     - pd_period_dtype.h:150
     - 


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

The following examples are extracted from the test suite.

.. _example-perioddtype-freq-0:

.. dropdown:: freq (pd_test_1_all.cpp:8233)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 8223
      :emphasize-lines: 11

          std::cout << "========= freq property ===============================";
      
          std::vector<std::optional<numpy::datetime64>> values = {
              numpy::datetime64(0LL, numpy::DateTimeUnit::Nanosecond),
              numpy::datetime64(86400000000000LL, numpy::DateTimeUnit::Nanosecond)  // 1 day
          };
          pandas::DatetimeArray arr(values);
          pandas::DatetimeMixinIndex idx(arr);
      
          // Default freq is nullopt or inferred
          auto f = idx.freq();
          std::string fs = idx.freqstr();
      
          bool passed = true;  // freq may or may not be set
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_datetime_mixin_freq()" << std::endl;
              throw std::runtime_error("pd_test_datetime_mixin_freq failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }

.. _example-perioddtype-freq_string-1:

.. dropdown:: freq_string (pd_test_1_all.cpp:15733)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 15723
      :emphasize-lines: 11

          bool passed = (isnan_mask.size() == 2);
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_period_index_isnan() : _isnan check failed" << std::endl;
              throw std::runtime_error("pd_test_period_index_isnan failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }
      
      // ============================================================================
      // unit() and freq_string() Tests
      // ============================================================================
      
      void pd_test_unit_freq_string() {
          std::cout << "========= unit() / freq_string() =========================";
      
          // PeriodIndex with monthly frequency
          numpy::NDArray<numpy::int64> data(std::vector<size_t>{1});
          data.setElementAt({0}, numpy::int64(0));
      
          numpy::NDArray<numpy::bool_> mask(std::vector<size_t>{1});

.. _example-perioddtype-kind-2:

.. dropdown:: kind (pd_test_1_all.cpp:300)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 290
      :emphasize-lines: 11

      
          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;

.. _example-perioddtype-matches-3:

.. dropdown:: matches (pd_test_5_all.cpp:15741)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 15731
      :emphasize-lines: 11

          for (size_t i = 0; i < 5; ++i) {
              // DatetimeIndex serializes individual entries via get_value_str()
              bdate_first5.push_back(idx.get_value_str(i));
          }
          std::cout << "  case_4 bdate_range first 5: ";
          for (auto& s : bdate_first5) std::cout << s << " ";
          std::cout << "\n  case_4 expected first 5:    ";
          for (auto& s : expected_visible_head) std::cout << s << " ";
          std::cout << "\n";
      
          // First date matches (both start at 2023-01-04)
          pandas_tests::check(contains(bdate_first5[0], "2023-01-04"),
                "case_4.first_bdate_is_2023-01-04", local_fail);
      
          // Second date should differ: bdate gives 2023-01-05, fixture wants 2023-01-20
          bool second_matches_expected = contains(bdate_first5[1], "2023-01-20");
          pandas_tests::check(!second_matches_expected,
                "case_4.bdate_NOT_matching_filtered_fixture", local_fail);
          // The bdate second is the next business day:
          pandas_tests::check(contains(bdate_first5[1], "2023-01-05"),
                "case_4.bdate_second_is_2023-01-05_sequential", local_fail);

.. _example-perioddtype-name-4:

.. dropdown:: name (pd_test_1_all.cpp:295)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 285
      :emphasize-lines: 11

                  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;

.. _example-perioddtype-repr-5:

.. dropdown:: repr (pd_test_1_all.cpp:10906)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10896
      :emphasize-lines: 11

          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;
      }
      

.. _example-perioddtype-type-6:

.. dropdown:: type (pd_test_3_all.cpp:15450)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 15440
      :emphasize-lines: 11

      /**
       * 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