pudl.transform.eia191
=====================

.. py:module:: pudl.transform.eia191

.. autoapi-nested-parse::

   Transform EIA Form 191 monthly underground natural gas storage data.



Attributes
----------

.. autoapisummary::

   pudl.transform.eia191.logger


Functions
---------

.. autoapisummary::

   pudl.transform.eia191.core_eia191__monthly_gas_storage


Module Contents
---------------

.. py:data:: logger

.. py:function:: core_eia191__monthly_gas_storage(raw_eia191__data: pandas.DataFrame) -> pandas.DataFrame

   Transform raw EIA-191 monthly underground natural gas storage data.

   One row per storage reservoir per month, identified by the EIA-assigned
   reservoir id and report_date.

   Transformations include:

   * Combine ``year`` and ``month`` into a single ``report_date`` column.
   * Normalize free-text string columns with
     :func:`pudl.helpers.simplify_strings` (lower-case, strip whitespace,
     remove non-standard characters).
   * Pass ``base_gas_mcf``, ``working_gas_capacity_mcf``, and
     ``total_field_capacity_mcf`` through as reported. These are operator
     self-reports under a loose EIA definition and are not additively
     consistent: ``total`` does not reliably equal ``working + base`` (~23%
     of rows differ). Do not assume additivity.

   :param raw_eia191__data: Concatenated raw CSV data from the PUDL EIA-191
                            Zenodo archive (RP8 monthly dataset, 2014–present).

   :returns: Cleaned monthly gas storage DataFrame with a combined report_date column.