QuarterBegin
============

.. cpp:class:: pandas::QuarterBegin

   pandas C++ class.

Example
-------

.. code-block:: cpp

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

   // Use QuarterBegin
   QuarterBegin obj;
   // ... operations ...

Aggregation
-----------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``numpy::datetime64 apply(const numpy::datetime64& dt) const override``
     - numpy::datetime64
     - pd_dateoffset.h:1139
     - :ref:`View <example-quarterbegin-apply-0>`

Comparison
----------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``int next_quarter_begin_month(int month) const``
     - int
     - pd_dateoffset.h:1172
     - 

Type Checking
-------------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``bool is_calendar_offset() const override``
     - bool
     - pd_dateoffset.h:1125
     - 
   * - ``bool is_on_offset(const numpy::datetime64& dt) const override``
     - bool
     - pd_dateoffset.h:1160
     - :ref:`View <example-quarterbegin-is_on_offset-1>`
   * - ``bool is_quarter_begin_month(int month) const``
     - bool
     - pd_dateoffset.h:1168
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``std::string freqstr() const override``
     - std::string
     - pd_dateoffset.h:1128
     - :ref:`View <example-quarterbegin-freqstr-2>`
   * - ``std::string name() const override { return freqstr()``
     - std::string
     - pd_dateoffset.h:1131
     - :ref:`View <example-quarterbegin-name-3>`
   * - ``int prev_quarter_begin_month(int month) const``
     - int
     - pd_dateoffset.h:1181
     - 
   * - ``std::string repr() const override``
     - std::string
     - pd_dateoffset.h:1132
     - :ref:`View <example-quarterbegin-repr-4>`
   * - ``int startingMonth() const``
     - int
     - pd_dateoffset.h:1123
     - :ref:`View <example-quarterbegin-startingmonth-5>`
   * - ``int64_t total_nanoseconds() const override``
     - int64_t
     - pd_dateoffset.h:1126
     - 


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

The following examples are extracted from the test suite.

.. _example-quarterbegin-apply-0:

.. dropdown:: apply (pd_test_1_all.cpp:11244)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 11234
      :emphasize-lines: 11

              void pd_test_func_apply_dataframe_apply_axis0() {
                  std::cout << "========= DataFrame apply axis=0 ======================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}},
                      {"B", {4.0, 5.0, 6.0}}
                  };
                  pandas::DataFrame df(data);
      
                  // apply axis=0 applies function to each column
                  auto result = df.apply([](const std::vector<double>& col) {
                      return std::accumulate(col.begin(), col.end(), 0.0);
                  }, 0);
      
                  bool passed = true;
      
                  // Plan F·dtype: axis=0 reduce now returns a single "result" column
                  // with the original column names ("A", "B") as the row index.
                  // Sum of A: 1+2+3=6, Sum of B: 4+5+6=15
                  const auto& result_col = result["result"];
                  double sum_a = std::stod(result_col.get_value_str(0));

.. _example-quarterbegin-is_on_offset-1:

.. dropdown:: is_on_offset (pd_test_3_all.cpp:18263)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 18253
      :emphasize-lines: 11

      
      void pd_test_business_day_offset() {
          std::cout << "========= BusinessDay offset ===========================";
      
          pandas::BusinessDay offset(1);
          if (offset.freqstr() != "B") {
              std::cout << "  [FAIL] : BusinessDay freqstr() failed" << std::endl;
              throw std::runtime_error("pd_test_business_day_offset: freqstr() failed");
          }
      
          // Test is_on_offset (Friday = weekday)
          numpy::datetime64 friday("2020-01-17");  // Friday
          if (!offset.is_on_offset(friday)) {
              std::cout << "  [FAIL] : BusinessDay is_on_offset(Friday) failed" << std::endl;
              throw std::runtime_error("pd_test_business_day_offset: is_on_offset(Friday) failed");
          }
      
          // Test is_on_offset (Saturday = weekend)
          numpy::datetime64 saturday("2020-01-18");  // Saturday
          if (offset.is_on_offset(saturday)) {
              std::cout << "  [FAIL] : BusinessDay is_on_offset(Saturday) should be false" << std::endl;

.. _example-quarterbegin-freqstr-2:

.. dropdown:: freqstr (pd_test_1_all.cpp:2671)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 2661
      :emphasize-lines: 11

              }
      
              pandas::PeriodDtype dtype_y("Y");
              if (dtype_y.name() != "period[Y]") {
                  std::cout << "  [FAIL] : dtype_y.name() should be 'period[Y]'" << std::endl;
                  throw std::runtime_error("pd_test_period_array_freq_validation failed: dtype name Y");
              }
      
              // Test frequency string
              pandas::PeriodArray arr(std::vector<std::string>{"2024-01-15"}, "D");
              if (arr.freqstr() != "D") {
                  std::cout << "  [FAIL] : arr.freqstr() should be 'D'" << std::endl;
                  throw std::runtime_error("pd_test_period_array_freq_validation failed: freqstr");
              }
      
              std::cout << " -> tests passed" << std::endl;
          }
      
          void pd_test_period_array_year_month_quarter() {
              std::cout << "========= PeriodArray: year/month/quarter components ======================= ";
      

.. _example-quarterbegin-name-3:

.. 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-quarterbegin-repr-4:

.. 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-quarterbegin-startingmonth-5:

.. dropdown:: startingMonth (pd_test_5_all.cpp:100867)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 100857
      :emphasize-lines: 11

          if (!off) return;
          const Concrete* cast = dynamic_cast<const Concrete*>(off.get());
          pandas_tests::check(cast != nullptr,
                              label + ".dynamic_cast", local_fail);
          if (!cast) {
              std::cout << "  got name=\"" << off->name() << "\"\n";
              return;
          }
          pandas_tests::check(cast->n() == expected_n,
                              label + ".n_matches", local_fail);
          pandas_tests::check(cast->startingMonth() == expected_starting_month,
                              label + ".starting_month_matches", local_fail);
          if (cast->startingMonth() != expected_starting_month) {
              std::cout << "  got startingMonth=" << cast->startingMonth()
                        << " expected startingMonth=" << expected_starting_month << "\n";
          }
      }
      
      static void check_factory_week(const std::string& label,
                                     const std::string& freq,
                                     int expected_n,