CellStyle
=========

.. cpp:class:: pandas::CellStyle

   Styling class for DataFrame rendering.

Example
-------

.. code-block:: cpp

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

   // Use CellStyle
   CellStyle obj;
   // ... operations ...

Combining
---------

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``void merge(const CellStyle& other)``
     - void
     - pd_styler.h:75
     - :ref:`View <example-cellstyle-merge-0>`

I/O
---

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``std::string to_css() const``
     - std::string
     - pd_styler.h:65
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``bool empty() const { return properties.empty()``
     - bool
     - pd_styler.h:81
     - :ref:`View <example-cellstyle-empty-1>`
   * - ``void set(const std::string& prop, const std::string& value)``
     - void
     - pd_styler.h:61
     - :ref:`View <example-cellstyle-set-2>`


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

The following examples are extracted from the test suite.

.. _example-cellstyle-merge-0:

.. 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-cellstyle-empty-1:

.. 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-cellstyle-set-2:

.. 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) {