Styler
======

.. cpp:class:: pandas::Styler

   Styling class for DataFrame rendering.

Example
-------

.. code-block:: cpp

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

   // Use Styler
   Styler obj;
   // ... operations ...

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

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

   * - Signature
     - Location
     - Example
   * - ``explicit Styler(const DataFrame& data)``
     - pd_styler.h:167
     - 
   * - ``Styler(const Styler& other)``
     - pd_styler.h:172
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``std::string get_cell_str(size_t row, size_t col) const``
     - std::string
     - pd_styler.h:137
     - 
   * - ``size_t get_col_index(const std::string& col_name) const``
     - size_t
     - pd_styler.h:130
     - 
   * - ``std::string get_column_name(size_t col) const``
     - std::string
     - pd_styler.h:143
     - 
   * - ``std::string get_index_str(size_t row) const``
     - std::string
     - pd_styler.h:140
     - 

Missing Data
------------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``static std::string interpolate_color(double normalized, const std::string& low_color, const std::string& high_color)``
     - static std::string
     - pd_styler.h:152
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``Styler& apply(ColumnStyleFunc func, std::optional<int> axis = 0, const StyleSubset& subset = {})``
     - Styler&
     - pd_styler.h:191
     - :ref:`View <example-styler-apply-0>`
   * - ``Styler& map(CellStyleFunc func, const StyleSubset& subset = {})``
     - Styler&
     - pd_styler.h:202
     - :ref:`View <example-styler-map-1>`
   * - ``auto pipe(Func func) -> decltype(func(\*this))``
     - auto
     - pd_styler.h:646
     - :ref:`View <example-styler-pipe-2>`

Combining
---------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``Styler& concat(const Styler& other)``
     - Styler&
     - pd_styler.h:637
     - :ref:`View <example-styler-concat-3>`

I/O
---

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``static std::optional<double> to_double(const std::string& s)``
     - static std::optional<double>
     - pd_styler.h:146
     - 
   * - ``std::string to_html(const std::string& table_uuid = "", const std::string& table_attributes = "", bool sparse_index = true, bool sparse_columns = true, bool bold_headers = false, const std::string& caption = "", const std::string& encoding = "utf-8", bool doctype_html = false, bool exclude_styles = false) const``
     - std::string
     - pd_styler.h:530
     - :ref:`View <example-styler-to_html-4>`
   * - ``void to_html(std::ostream& buf, const std::string& table_uuid = "", const std::string& table_attributes = "", bool sparse_index = true, bool sparse_columns = true, bool bold_headers = false, const std::string& caption = "", const std::string& encoding = "utf-8", bool doctype_html = false, bool exclude_styles = false) const``
     - void
     - pd_styler.h:543
     - :ref:`View <example-styler-to_html-5>`
   * - ``std::string to_latex(const std::string& column_format = "", const std::string& position = "", const std::string& position_float = "", bool hrules = false, const std::string& clines = "", const std::string& label = "", const std::string& caption = "", bool sparse_index = true, bool sparse_columns = true, const std::string& multirow_align = "c", const std::string& multicol_align = "r", bool siunitx = false, const std::string& environment = "", const std::string& encoding = "utf-8", bool convert_css = false) const``
     - std::string
     - pd_styler.h:574
     - :ref:`View <example-styler-to_latex-6>`
   * - ``void to_latex(std::ostream& buf, const std::string& column_format = "", const std::string& position = "", const std::string& position_float = "", bool hrules = false, const std::string& clines = "", const std::string& label = "", const std::string& caption = "", bool sparse_index = true, bool sparse_columns = true, const std::string& multirow_align = "c", const std::string& multicol_align = "r", bool siunitx = false, const std::string& environment = "", const std::string& encoding = "utf-8", bool convert_css = false) const``
     - void
     - pd_styler.h:593
     - :ref:`View <example-styler-to_latex-7>`
   * - ``std::string to_string(bool sparse_index = true, bool sparse_columns = true) const``
     - std::string
     - pd_styler.h:617
     - :ref:`View <example-styler-to_string-8>`
   * - ``void to_string(std::ostream& buf, bool sparse_index = true, bool sparse_columns = true) const``
     - void
     - pd_styler.h:623
     - :ref:`View <example-styler-to_string-9>`

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``Styler& background_gradient(const std::string& cmap = "PuBu", double low = 0.0, double high = 0.0, std::optional<int> axis = 0, const StyleSubset& subset = {}, double text_color_threshold = 0.408, std::optional<double> vmin = std::nullopt, std::optional<double> vmax = std::nullopt)``
     - Styler&
     - pd_styler.h:305
     - :ref:`View <example-styler-background_gradient-10>`
   * - ``Styler& bar(const StyleSubset& subset = {}, std::optional<int> axis = 0, const std::string& color = "#d65f5f", const std::string& cmap = "", double width = 100.0, double height = 100.0, const std::string& align = "left", std::optional<double> vmin = std::nullopt, std::optional<double> vmax = std::nullopt)``
     - Styler&
     - pd_styler.h:345
     - :ref:`View <example-styler-bar-11>`
   * - ``Styler& clear()``
     - Styler&
     - pd_styler.h:495
     - :ref:`View <example-styler-clear-12>`
   * - ``const DataFrame& data() const``
     - const DataFrame&
     - pd_styler.h:653
     - :ref:`View <example-styler-data-13>`
   * - ``void ensure_style_matrices()``
     - void
     - pd_styler.h:127
     - 
   * - ``static std::string escape_html(const std::string& str)``
     - static std::string
     - pd_styler.h:149
     - 
   * - ``std::vector<std::map<std::string, std::string>> export_styles() const``
     - std::vector<std::map<std::string, std::string>>
     - pd_styler.h:502
     - 
   * - ``Styler& format(const std::string& formatter = "", const StyleSubset& subset = {}, const std::string& na_rep = "", int precision = -1, const std::string& thousands = "", bool escape = true)``
     - Styler&
     - pd_styler.h:370
     - :ref:`View <example-styler-format-14>`
   * - ``Styler& format(const std::map<std::string, std::string>& formatters, const std::string& na_rep = "", int precision = -1, bool escape = true)``
     - Styler&
     - pd_styler.h:380
     - :ref:`View <example-styler-format-15>`
   * - ``Styler& hide(const StyleSubset& subset = {}, std::optional<int> axis = std::nullopt, const std::vector<int>& level = {}, bool names = false)``
     - Styler&
     - pd_styler.h:481
     - :ref:`View <example-styler-hide-16>`
   * - ``Styler& highlight_between(const StyleSubset& subset = {}, const std::string& color = "yellow", std::optional<int> axis = std::nullopt, std::optional<double> left = std::nullopt, std::optional<double> right = std::nullopt, const std::string& inclusive = "both", const std::string& props = "")``
     - Styler&
     - pd_styler.h:260
     - :ref:`View <example-styler-highlight_between-17>`
   * - ``Styler& highlight_max(const StyleSubset& subset = {}, const std::string& color = "yellow", std::optional<int> axis = 0, const std::string& props = "")``
     - Styler&
     - pd_styler.h:229
     - :ref:`View <example-styler-highlight_max-18>`
   * - ``Styler& highlight_min(const StyleSubset& subset = {}, const std::string& color = "yellow", std::optional<int> axis = 0, const std::string& props = "")``
     - Styler&
     - pd_styler.h:243
     - :ref:`View <example-styler-highlight_min-19>`
   * - ``Styler& highlight_null(const std::string& color = "red", const StyleSubset& subset = {}, const std::string& props = "")``
     - Styler&
     - pd_styler.h:216
     - :ref:`View <example-styler-highlight_null-20>`
   * - ``Styler& highlight_quantile(const StyleSubset& subset = {}, const std::string& color = "yellow", std::optional<int> axis = 0, double q_left = 0.0, double q_right = 1.0, const std::string& inclusive = "both", const std::string& props = "")``
     - Styler&
     - pd_styler.h:280
     - :ref:`View <example-styler-highlight_quantile-21>`
   * - ``static std::tuple<int, int, int> parse_color(const std::string& color)``
     - static std::tuple<int, int, int>
     - pd_styler.h:157
     - 
   * - ``std::string render() const { return to_html()``
     - std::string
     - pd_styler.h:658
     - :ref:`View <example-styler-render-22>`
   * - ``std::pair<std::vector<size_t>, std::vector<size_t>> resolve_subset( const StyleSubset& subset) const``
     - std::pair<std::vector<size_t>, std::vector<size_t>>
     - pd_styler.h:133
     - 
   * - ``static std::string rgb_to_hex(int r, int g, int b)``
     - static std::string
     - pd_styler.h:160
     - 
   * - ``Styler& set_caption(const std::string& caption)``
     - Styler&
     - pd_styler.h:434
     - :ref:`View <example-styler-set_caption-23>`
   * - ``Styler& set_properties(const std::map<std::string, std::string>& props, const StyleSubset& subset = {})``
     - Styler&
     - pd_styler.h:396
     - :ref:`View <example-styler-set_properties-24>`
   * - ``Styler& set_sticky(std::optional<int> axis = 0, std::optional<int> pixel_size = std::nullopt, const std::vector<int>& levels = {})``
     - Styler&
     - pd_styler.h:464
     - 
   * - ``Styler& set_table_attributes(const std::string& attributes)``
     - Styler&
     - pd_styler.h:418
     - 
   * - ``Styler& set_table_styles( const std::vector<std::pair<std::string, std::string>>& table_styles, std::optional<int> axis = std::nullopt, bool overwrite = false)``
     - Styler&
     - pd_styler.h:407
     - :ref:`View <example-styler-set_table_styles-25>`
   * - ``Styler& set_td_classes(const std::vector<std::vector<std::string>>& classes)``
     - Styler&
     - pd_styler.h:426
     - 
   * - ``Styler& set_tooltips(const std::vector<std::vector<std::string>>& ttips, const std::string& props = "", const std::string& css_class = "")``
     - Styler&
     - pd_styler.h:444
     - 
   * - ``Styler& set_uuid(const std::string& uuid)``
     - Styler&
     - pd_styler.h:454
     - :ref:`View <example-styler-set_uuid-26>`
   * - ``Styler& text_gradient(const std::string& cmap = "PuBu", double low = 0.0, double high = 0.0, std::optional<int> axis = 0, const StyleSubset& subset = {}, std::optional<double> vmin = std::nullopt, std::optional<double> vmax = std::nullopt)``
     - Styler&
     - pd_styler.h:319
     - :ref:`View <example-styler-text_gradient-27>`
   * - ``Styler& use(const std::vector<std::map<std::string, std::string>>& styles)``
     - Styler&
     - pd_styler.h:510
     - 


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

The following examples are extracted from the test suite.

.. _example-styler-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-styler-map-1:

.. dropdown:: map (pd_test_1_all.cpp:5839)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 5829
      :emphasize-lines: 11

      // Map Tests
      // ============================================================================
      
      void pd_test_categorical_index_map() {
          std::cout << "========= map =========================================";
      
          pandas::CategoricalArray arr({"yes", "no", "yes"});
          pandas::CategoricalIndex idx(arr);
      
          std::unordered_map<std::string, std::string> mapping = {{"yes", "1"}, {"no", "0"}};
          pandas::CategoricalIndex mapped = idx.map(mapping);
      
          bool passed = (mapped.has_category("1") && mapped.has_category("0") &&
                         !mapped.has_category("yes") && !mapped.has_category("no"));
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_categorical_index_map()" << std::endl;
              throw std::runtime_error("pd_test_categorical_index_map failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }

.. _example-styler-pipe-2:

.. dropdown:: pipe (pd_test_1_all.cpp:11164)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 11154
      :emphasize-lines: 11

                  // Pipe applies function to entire Series
                  auto add_mean = [](const pandas::Series<double>& ser, double offset) {
                      auto mean_val = ser.mean();
                      std::vector<double> result;
                      for (size_t i = 0; i < ser.size(); ++i) {
                          result.push_back(ser[i] + mean_val.value_or(0.0) + offset);
                      }
                      return pandas::Series<double>(result, ser.name());
                  };
      
                  auto result = s.pipe(add_mean, 10.0);
      
                  bool passed = true;
                  // mean is 2.5, offset is 10.0, so each value + 12.5
                  std::vector<double> expected = {13.5, 14.5, 15.5, 16.5};
                  for (size_t i = 0; i < result.size(); ++i) {
                      if (!approx_equal(result[i], expected[i])) {
                          passed = false;
                          std::cout << "  [FAIL] : in pd_test_func_apply_series_pipe() : value mismatch at " << i << std::endl;
                          throw std::runtime_error("pd_test_func_apply_series_pipe failed: value mismatch");
                      }

.. _example-styler-concat-3:

.. dropdown:: concat (pd_test_1_all.cpp:17717)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 17707
      :emphasize-lines: 11

      }
      
      void pd_test_period_index_concat() {
          std::cout << "========= concat factory ==============================";
      
          std::vector<int64_t> ordinals1 = {0, 1};
          std::vector<int64_t> ordinals2 = {2, 3};
          pandas::PeriodIndex idx1(ordinals1, "D");
          pandas::PeriodIndex idx2(ordinals2, "D");
      
          pandas::PeriodIndex concatenated = pandas::PeriodIndex::concat({idx1, idx2});
      
          bool passed = (concatenated.size() == 4);
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_period_index_concat()" << std::endl;
              throw std::runtime_error("pd_test_period_index_concat failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }
      

.. _example-styler-to_html-4:

.. dropdown:: to_html (pd_test_1_all.cpp:13438)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 13428
      :emphasize-lines: 11

      
              void pd_test_io_to_html() {
                  std::cout << "========= to_html ================================";
      
                  std::map<std::string, std::vector<double>> data;
                  data["A"] = {1.0, 2.0};
                  data["B"] = {3.0, 4.0};
      
                  pandas::DataFrame df(data);
      
                  std::string html = df.to_html();
      
                  // Check for key HTML elements
                  bool has_table = (html.find("<table") != std::string::npos);
                  bool has_thead = (html.find("<thead>") != std::string::npos);
                  bool has_tbody = (html.find("<tbody>") != std::string::npos);
                  bool has_th = (html.find("<th>") != std::string::npos);
                  bool has_td = (html.find("<td>") != std::string::npos);
      
                  bool passed = has_table && has_thead && has_tbody && has_th && has_td;
      

.. _example-styler-to_html-5:

.. dropdown:: to_html (pd_test_1_all.cpp:13438)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 13428
      :emphasize-lines: 11

      
              void pd_test_io_to_html() {
                  std::cout << "========= to_html ================================";
      
                  std::map<std::string, std::vector<double>> data;
                  data["A"] = {1.0, 2.0};
                  data["B"] = {3.0, 4.0};
      
                  pandas::DataFrame df(data);
      
                  std::string html = df.to_html();
      
                  // Check for key HTML elements
                  bool has_table = (html.find("<table") != std::string::npos);
                  bool has_thead = (html.find("<thead>") != std::string::npos);
                  bool has_tbody = (html.find("<tbody>") != std::string::npos);
                  bool has_th = (html.find("<th>") != std::string::npos);
                  bool has_td = (html.find("<td>") != std::string::npos);
      
                  bool passed = has_table && has_thead && has_tbody && has_th && has_td;
      

.. _example-styler-to_latex-6:

.. dropdown:: to_latex (pd_test_2_all.cpp:9446)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9436
      :emphasize-lines: 11

              void pd_test_styler_to_latex() {
                  std::cout << "========= to_latex =================================";
      
                  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);
      
                  auto styler = df.style();
                  std::string latex = styler.to_latex();
      
                  if (!contains(latex, "\\begin{tabular}")) {
                      std::cout << "  [FAIL] : in pd_test_styler_to_latex() : did not produce tabular environment" << std::endl;
                      throw std::runtime_error("pd_test_styler_to_latex failed: did not produce tabular environment");
                  }
                  if (!contains(latex, "\\end{tabular}")) {
                      std::cout << "  [FAIL] : in pd_test_styler_to_latex() : did not close tabular environment" << std::endl;
                      throw std::runtime_error("pd_test_styler_to_latex failed: did not close tabular environment");
                  }
      

.. _example-styler-to_latex-7:

.. dropdown:: to_latex (pd_test_2_all.cpp:9446)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9436
      :emphasize-lines: 11

              void pd_test_styler_to_latex() {
                  std::cout << "========= to_latex =================================";
      
                  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);
      
                  auto styler = df.style();
                  std::string latex = styler.to_latex();
      
                  if (!contains(latex, "\\begin{tabular}")) {
                      std::cout << "  [FAIL] : in pd_test_styler_to_latex() : did not produce tabular environment" << std::endl;
                      throw std::runtime_error("pd_test_styler_to_latex failed: did not produce tabular environment");
                  }
                  if (!contains(latex, "\\end{tabular}")) {
                      std::cout << "  [FAIL] : in pd_test_styler_to_latex() : did not close tabular environment" << std::endl;
                      throw std::runtime_error("pd_test_styler_to_latex failed: did not close tabular environment");
                  }
      

.. _example-styler-to_string-8:

.. dropdown:: to_string (pd_test_1_all.cpp:2693)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 2683
      :emphasize-lines: 11

              pandas::PeriodArray arr_m(std::vector<std::string>{
                  "2020-01",
                  "NaT",
                  "2025-06"
              }, "M");
      
              // Year
              auto years = arr_m.year();
              auto y0 = years[0];
              if (!y0.has_value() || y0.value() != 2020) {
                  std::cout << "  [FAIL] : year[0] should be 2020, got " << (y0.has_value() ? std::to_string(y0.value()) : "NA") << std::endl;
                  throw std::runtime_error("pd_test_period_array_year_month_quarter failed: year[0]");
              }
      
              auto y1 = years[1];
              if (y1.has_value()) {
                  std::cout << "  [FAIL] : year[1] should be NA (NaT)" << std::endl;
                  throw std::runtime_error("pd_test_period_array_year_month_quarter failed: year[1] should be NA");
              }
      
              auto y2 = years[2];

.. _example-styler-to_string-9:

.. dropdown:: to_string (pd_test_1_all.cpp:2693)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 2683
      :emphasize-lines: 11

              pandas::PeriodArray arr_m(std::vector<std::string>{
                  "2020-01",
                  "NaT",
                  "2025-06"
              }, "M");
      
              // Year
              auto years = arr_m.year();
              auto y0 = years[0];
              if (!y0.has_value() || y0.value() != 2020) {
                  std::cout << "  [FAIL] : year[0] should be 2020, got " << (y0.has_value() ? std::to_string(y0.value()) : "NA") << std::endl;
                  throw std::runtime_error("pd_test_period_array_year_month_quarter failed: year[0]");
              }
      
              auto y1 = years[1];
              if (y1.has_value()) {
                  std::cout << "  [FAIL] : year[1] should be NA (NaT)" << std::endl;
                  throw std::runtime_error("pd_test_period_array_year_month_quarter failed: year[1] should be NA");
              }
      
              auto y2 = years[2];

.. _example-styler-background_gradient-10:

.. dropdown:: background_gradient (pd_test_2_all.cpp:9286)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9276
      :emphasize-lines: 11

      
              void pd_test_styler_background_gradient() {
                  std::cout << "========= background_gradient ======================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0, 4.0, 5.0}},
                      {"B", {10.0, 20.0, 30.0, 40.0, 50.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().background_gradient();
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: #")) {
                      std::cout << "  [FAIL] : in pd_test_styler_background_gradient() : did not apply color styles" << std::endl;
                      throw std::runtime_error("pd_test_styler_background_gradient failed: did not apply color styles");
                  }
      
                  auto styler2 = df.style().background_gradient("Reds");
                  std::string html2 = styler2.to_html();
      

.. _example-styler-bar-11:

.. dropdown:: bar (pd_test_2_all.cpp:9332)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9322
      :emphasize-lines: 11

              }
      
              void pd_test_styler_bar() {
                  std::cout << "========= bar ======================================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {10.0, 30.0, 50.0, 70.0, 100.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().bar();
                  std::string html = styler.to_html();
      
                  if (!contains(html, "linear-gradient")) {
                      std::cout << "  [FAIL] : in pd_test_styler_bar() : did not apply gradient background" << std::endl;
                      throw std::runtime_error("pd_test_styler_bar failed: did not apply gradient background");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-clear-12:

.. 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-styler-data-13:

.. dropdown:: data (pd_test_1_all.cpp:9114)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9104
      :emphasize-lines: 11

              throw std::runtime_error("pd_test_datetime_mixin_default_constructor failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }
      
      void pd_test_datetime_mixin_array_constructor() {
          std::cout << "========= DatetimeTDMixin array constructor =========================";
      
          // Create DatetimeArray with some values
          numpy::NDArray<numpy::datetime64> data(std::vector<size_t>{3});
          data.setElementAt({0}, numpy::datetime64(1000000000000000000LL, numpy::DateTimeUnit::Nanosecond));  // ~2001
          data.setElementAt({1}, numpy::datetime64(1500000000000000000LL, numpy::DateTimeUnit::Nanosecond));  // ~2017
          data.setElementAt({2}, numpy::datetime64(1600000000000000000LL, numpy::DateTimeUnit::Nanosecond));  // ~2020
      
          numpy::NDArray<numpy::bool_> mask(std::vector<size_t>{3});
          mask.setElementAt({0}, numpy::bool_(false));
          mask.setElementAt({1}, numpy::bool_(false));
          mask.setElementAt({2}, numpy::bool_(false));
      
          pandas::DatetimeArray arr(data, mask);

.. _example-styler-format-14:

.. dropdown:: format (main.cpp:20)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10
      :emphasize-lines: 11

      int main() {
        // Automatically log all output to temp/pd_test_output.log
        numpy::TestLogger logger("temp/pd_test_output.log");
      
        int res = 0;
        int res1 = 0;
        std::string resS = "";
      
        // call all the tests
        res1 = dataframe_tests::pd_test_main();
        resS += std::format("             pd_test_main: {}  errors\n", res1);
        res += res1;
      
        std::cout << "\n------------------------- main --------------------------------------------\n";
        std::cout << std::endl << "All tests completed. Nb errors = " << res << std::endl;
        std::cout << "Details: \n" << resS;
        std::cout << "\n---------------------------------------------------------------------------\n";
        return res;
      }

.. _example-styler-format-15:

.. dropdown:: format (main.cpp:20)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10
      :emphasize-lines: 11

      int main() {
        // Automatically log all output to temp/pd_test_output.log
        numpy::TestLogger logger("temp/pd_test_output.log");
      
        int res = 0;
        int res1 = 0;
        std::string resS = "";
      
        // call all the tests
        res1 = dataframe_tests::pd_test_main();
        resS += std::format("             pd_test_main: {}  errors\n", res1);
        res += res1;
      
        std::cout << "\n------------------------- main --------------------------------------------\n";
        std::cout << std::endl << "All tests completed. Nb errors = " << res << std::endl;
        std::cout << "Details: \n" << resS;
        std::cout << "\n---------------------------------------------------------------------------\n";
        return res;
      }

.. _example-styler-hide-16:

.. dropdown:: hide (pd_test_2_all.cpp:9420)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9410
      :emphasize-lines: 11

                  std::cout << "========= hide =====================================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}},
                      {"B", {4.0, 5.0, 6.0}},
                      {"C", {7.0, 8.0, 9.0}}
                  };
                  pandas::DataFrame df(data);
      
                  pandas::StyleSubset subset({"B"});
                  auto styler = df.style().hide(subset, 0);
                  std::string html = styler.to_html();
      
                  if (contains(html, "<th>B</th>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_hide() : did not hide column B" << std::endl;
                      throw std::runtime_error("pd_test_styler_hide failed: did not hide column B");
                  }
      
                  if (!contains(html, "<th>A</th>") || !contains(html, "<th>C</th>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_hide() : removed wrong columns" << std::endl;
                      throw std::runtime_error("pd_test_styler_hide failed: removed wrong columns");

.. _example-styler-highlight_between-17:

.. dropdown:: highlight_between (pd_test_2_all.cpp:9266)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9256
      :emphasize-lines: 11

      
              void pd_test_styler_highlight_between() {
                  std::cout << "========= highlight_between ========================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 5.0, 10.0}},
                      {"B", {2.0, 6.0, 8.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().highlight_between({}, "lightblue", std::nullopt, 3.0, 7.0);
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: lightblue")) {
                      std::cout << "  [FAIL] : in pd_test_styler_highlight_between() : did not apply lightblue background" << std::endl;
                      throw std::runtime_error("pd_test_styler_highlight_between failed: did not apply lightblue background");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-highlight_max-18:

.. dropdown:: highlight_max (pd_test_2_all.cpp:9188)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9178
      :emphasize-lines: 11

              void pd_test_styler_highlight_max() {
                  std::cout << "========= highlight_max ============================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 3.0, 2.0}},
                      {"B", {4.0, 5.0, 6.0}}
                  };
                  pandas::DataFrame df(data);
      
                  // Highlight max with default color (yellow)
                  auto styler = df.style().highlight_max();
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: yellow")) {
                      std::cout << "  [FAIL] : in pd_test_styler_highlight_max() : did not apply yellow background" << std::endl;
                      throw std::runtime_error("pd_test_styler_highlight_max failed: did not apply yellow background");
                  }
      
                  // Test with custom color
                  auto styler2 = df.style().highlight_max({}, "lightgreen");
                  std::string html2 = styler2.to_html();

.. _example-styler-highlight_min-19:

.. dropdown:: highlight_min (pd_test_2_all.cpp:9217)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9207
      :emphasize-lines: 11

      
              void pd_test_styler_highlight_min() {
                  std::cout << "========= highlight_min ============================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 3.0, 2.0}},
                      {"B", {4.0, 5.0, 6.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().highlight_min();
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: yellow")) {
                      std::cout << "  [FAIL] : in pd_test_styler_highlight_min() : did not apply yellow background" << std::endl;
                      throw std::runtime_error("pd_test_styler_highlight_min failed: did not apply yellow background");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-highlight_null-20:

.. dropdown:: highlight_null (pd_test_2_all.cpp:9237)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9227
      :emphasize-lines: 11

      
              void pd_test_styler_highlight_null() {
                  std::cout << "========= highlight_null ===========================";
      
                  std::map<std::string, std::vector<std::string>> data = {
                      {"A", {"1.0", "NaN", "3.0"}},
                      {"B", {"4.0", "5.0", "NA"}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().highlight_null();
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: red")) {
                      std::cout << "  [FAIL] : in pd_test_styler_highlight_null() : did not apply red background" << std::endl;
                      throw std::runtime_error("pd_test_styler_highlight_null failed: did not apply red background");
                  }
      
                  // Test with custom color
                  auto styler2 = df.style().highlight_null("orange");
                  std::string html2 = styler2.to_html();

.. _example-styler-highlight_quantile-21:

.. dropdown:: highlight_quantile (pd_test_2_all.cpp:9672)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9662
      :emphasize-lines: 11

              }
      
              void pd_test_styler_highlight_quantile() {
                  std::cout << "========= highlight_quantile =======================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().highlight_quantile({}, "lightgreen", 0, 0.8, 1.0);
                  std::string html = styler.to_html();
      
                  if (!contains(html, "background-color: lightgreen")) {
                      std::cout << "  [FAIL] : in pd_test_styler_highlight_quantile() : did not apply highlight" << std::endl;
                      throw std::runtime_error("pd_test_styler_highlight_quantile failed: did not apply highlight");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-render-22:

.. dropdown:: render (pd_test_2_all.cpp:9161)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9151
      :emphasize-lines: 11

                  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);
      
                  // Get Styler
                  auto styler = df.style();
      
                  // Check that render produces HTML
                  std::string html = styler.render();
                  if (!contains(html, "<table>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_basic() : render() did not produce table tag" << std::endl;
                      throw std::runtime_error("pd_test_styler_basic failed: render() did not produce table tag");
                  }
                  if (!contains(html, "<th>A</th>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_basic() : render() did not include column header A" << std::endl;
                      throw std::runtime_error("pd_test_styler_basic failed: render() did not include column header A");
                  }
                  if (!contains(html, "<th>B</th>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_basic() : render() did not include column header B" << std::endl;

.. _example-styler-set_caption-23:

.. dropdown:: set_caption (pd_test_2_all.cpp:9370)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9360
      :emphasize-lines: 11

              }
      
              void pd_test_styler_set_caption() {
                  std::cout << "========= set_caption ==============================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().set_caption("My Data Table");
                  std::string html = styler.to_html();
      
                  if (!contains(html, "<caption>My Data Table</caption>")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_caption() : did not add caption element" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_caption failed: did not add caption element");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-set_properties-24:

.. dropdown:: set_properties (pd_test_2_all.cpp:9394)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9384
      :emphasize-lines: 11

                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0}},
                      {"B", {3.0, 4.0}}
                  };
                  pandas::DataFrame df(data);
      
                  std::map<std::string, std::string> props = {
                      {"font-weight", "bold"},
                      {"text-align", "center"}
                  };
                  auto styler = df.style().set_properties(props);
                  std::string html = styler.to_html();
      
                  if (!contains(html, "font-weight: bold")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_properties() : did not apply font-weight" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_properties failed: did not apply font-weight");
                  }
                  if (!contains(html, "text-align: center")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_properties() : did not apply text-align" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_properties failed: did not apply text-align");
                  }

.. _example-styler-set_table_styles-25:

.. dropdown:: set_table_styles (pd_test_2_all.cpp:9696)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9686
      :emphasize-lines: 11

                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}}
                  };
                  pandas::DataFrame df(data);
      
                  std::vector<std::pair<std::string, std::string>> styles = {
                      {"th", "background-color: lightgray;"},
                      {"td", "padding: 10px;"}
                  };
      
                  auto styler = df.style().set_table_styles(styles);
                  std::string html = styler.to_html();
      
                  if (!contains(html, "<style type=\"text/css\">")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_table_styles() : did not add style block" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_table_styles failed: did not add style block");
                  }
                  if (!contains(html, "th { background-color: lightgray; }")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_table_styles() : did not include th style" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_table_styles failed: did not include th style");
                  }

.. _example-styler-set_uuid-26:

.. dropdown:: set_uuid (pd_test_2_all.cpp:9653)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9643
      :emphasize-lines: 11

              }
      
              void pd_test_styler_set_uuid() {
                  std::cout << "========= set_uuid =================================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().set_uuid("my-custom-table-id");
                  std::string html = styler.to_html();
      
                  if (!contains(html, "id=\"my-custom-table-id\"")) {
                      std::cout << "  [FAIL] : in pd_test_styler_set_uuid() : did not set table id" << std::endl;
                      throw std::runtime_error("pd_test_styler_set_uuid failed: did not set table id");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }
      

.. _example-styler-text_gradient-27:

.. dropdown:: text_gradient (pd_test_2_all.cpp:9313)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 9303
      :emphasize-lines: 11

              }
      
              void pd_test_styler_text_gradient() {
                  std::cout << "========= text_gradient ============================";
      
                  std::map<std::string, std::vector<double>> data = {
                      {"A", {1.0, 2.0, 3.0}}
                  };
                  pandas::DataFrame df(data);
      
                  auto styler = df.style().text_gradient("Blues");
                  std::string html = styler.to_html();
      
                  if (!contains(html, "color: #")) {
                      std::cout << "  [FAIL] : in pd_test_styler_text_gradient() : did not apply text color styles" << std::endl;
                      throw std::runtime_error("pd_test_styler_text_gradient failed: did not apply text color styles");
                  }
      
                  std::cout << " -> tests passed" << std::endl;
              }