.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "examples/disciplines/basics/plot_data_frame.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_examples_disciplines_basics_plot_data_frame.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_examples_disciplines_basics_plot_data_frame.py:


Create a discipline that uses pandas DataFrames
===============================================

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.. code-block:: Python


    from __future__ import annotations

    from pandas import DataFrame

    from gemseo import configure_logger
    from gemseo.core.discipline import MDODiscipline








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Import
------

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.. code-block:: Python


    configure_logger()






.. rst-class:: sphx-glr-script-out

 .. code-block:: none


    <RootLogger root (INFO)>



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Create a discipline that uses a DataFrame
-----------------------------------------

We will create a class for a simple discipline that computes an output
variable ``y = 1 - 0.2 * x`` where ``x`` is an input variable.
For whatever reason, the business logic of this discipline uses a pandas DataFrame
to store the input and output values outside |g|.
Although |g| disciplines only handle input and output variables that are NumPy arrays,
their local data and default input values can use DataFrame objects.

The input and output grammars of the discipline shall use a naming convention
to access the names of the columns of a DataFrame.
The naming convention is built with the name of the input or output,
the character ``~`` (this can be changed) and
the name of the DataFrame column.

The code executed by the discipline is in the ``_run`` method,
where ``self.local_data``, i.e. the local data, has automatically been initialized
with the default inputs and updated with the inputs passed to the discipline.
A DataFrame can be retrieved by querying the corresponding key, e.g. ``df``,
in the local data and then changes can be made to this DataFrame, e.g.
``discipline.local_data["df"]["x"] = value``.

The default inputs and local data are instances of :class:`.DisciplineData`.

.. seealso::

 :class:`.DisciplineData` has more information about how DataFrames are handled.

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.. code-block:: Python



    class DataFrameDiscipline(MDODiscipline):
        def __init__(self) -> None:
            super().__init__(grammar_type=MDODiscipline.GrammarType.SIMPLE)
            self.input_grammar.update_from_names(["df~x"])
            self.output_grammar.update_from_names(["df~y"])
            self.default_inputs = {"df": DataFrame(data={"x": [0.0]})}

        def _run(self) -> None:
            df = self.local_data["df"]
            df["y"] = 1.0 - 0.2 * df["x"]

            # The code above could also have been written as
            # self.local_data["df~y"] = 1.0 - 0.2 * self.local_data["df~x"]
            # self.local_data["df"]["y"] = 1.0 - 0.2 * self.local_data["df"]["x"]









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Instantiate the discipline
--------------------------

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.. code-block:: Python

    discipline = DataFrameDiscipline()








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Execute the discipline
----------------------
Then, we can execute it easily, either considering default inputs:

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.. code-block:: Python

    discipline.execute()





.. rst-class:: sphx-glr-script-out

 .. code-block:: none


    {'df':      x    y
    0  0.0  1.0}



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or using new inputs:

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.. code-block:: Python

    discipline.execute({"df~x": [1.0]})




.. rst-class:: sphx-glr-script-out

 .. code-block:: none


    {'df':      x    y
    0  1.0  0.8}




.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.015 seconds)


.. _sphx_glr_download_examples_disciplines_basics_plot_data_frame.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_data_frame.ipynb <plot_data_frame.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_data_frame.py <plot_data_frame.py>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_