.. _bskPrinciples-6a:

Importing External Data Sources
===============================

Basilisk provides a range of simulation support data.  You can see the Basilisk
provided data sets in :ref:`supportDataList`.  The data is organized into topical folders
which contain the data files.

The data importing is handled with :ref:`dataFetcher`.  This process pulls the data
file from the local ``basilisk/supportData`` folder if it exists (repo was cloned),
or from the ``pooch`` cache if it was downloaded by ``pooch`` data management package.

At the top of your simulation script, import the data fetching tools using::

    from Basilisk.utilities.supportDataTools.dataFetcher import get_path, DataFile

Next, if you want to import a file ``GGM2BData`` inside the folder ``LocalGravData``, then
use::

    ggm2b_path = get_path(DataFile.LocalGravData.GGM2BData)

Note that the file extension is not needed, only the file name.
To set the data file path as a string to a Basilisk module, you can use::

    planet.useSphericalHarmonicsGravityModel(str(ggm2b_path), 100)