LocProxy
========

.. cpp:class:: pandas::LocProxy

   pandas C++ class.

Example
-------

.. code-block:: cpp

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

   // Use LocProxy
   LocProxy obj;
   // ... operations ...

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

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

   * - Signature
     - Location
     - Example
   * - ``LocProxy(DataFrame& df, const std::string& label1, const std::string& label2)``
     - pd_dataframe.h:3652
     - 

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

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

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``operator DataFrame() const``
     - operator
     - pd_dataframe.h:3693
     - :ref:`View <example-locproxy-dataframe-0>`


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

The following examples are extracted from the test suite.

.. _example-locproxy-dataframe-0:

.. dropdown:: DataFrame (pd_test_1_all.cpp:22011)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 22001
      :emphasize-lines: 11

      
              void pd_test_where_basic() {
                  std::cout << "========= where basic functionality =======================";
      
                  // Create DataFrame
                  std::map<std::string, std::vector<double>> data;
                  data["A"] = {1.0, 2.0, 3.0, 4.0};
                  data["B"] = {5.0, 6.0, 7.0, 8.0};
                  pandas::DataFrame df(data);
      
                  // Create condition DataFrame (values > 2)
                  std::map<std::string, std::vector<numpy::bool_>> cond_data;
                  cond_data["A"] = {false, false, true, true};   // 1<=2, 2<=2, 3>2, 4>2
                  cond_data["B"] = {true, true, true, true};     // all >2
                  pandas::DataFrame cond(cond_data);
      
                  // Apply where with replacement value -1
                  pandas::DataFrame result = df.where(cond, -1.0);
      
                  // Get column index for A - it's sorted alphabetically in std::map
                  size_t col_a_idx = df.get_column_index("A");