epicsarchiver.retrieval.archive_event
=====================================

.. py:module:: epicsarchiver.retrieval.archive_event

.. autoapi-nested-parse::

   Archive Event module for the ArchiveEvent class.



Classes
-------

.. autoapisummary::

   epicsarchiver.retrieval.archive_event.FieldValue
   epicsarchiver.retrieval.archive_event.ArchiveEvent


Functions
---------

.. autoapisummary::

   epicsarchiver.retrieval.archive_event.year_timestamp
   epicsarchiver.retrieval.archive_event.ysn_timestamp
   epicsarchiver.retrieval.archive_event.dataframe_from_events


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

.. py:class:: FieldValue

   Basic representation of a changed field value from an archive event.

   :returns: Pair of name and value
   :rtype: FieldValue


   .. py:attribute:: name
      :type:  str | None


   .. py:attribute:: value
      :type:  str | None


.. py:class:: ArchiveEvent

   One Event, retrieved from the AA, representing a change in value of a PV.


   .. py:attribute:: pv
      :type:  str


   .. py:attribute:: val
      :type:  int | float | str | list[str] | list[int] | list[float] | bytes


   .. py:attribute:: secondsintoyear
      :type:  int


   .. py:attribute:: year
      :type:  int


   .. py:attribute:: nanos
      :type:  int


   .. py:attribute:: severity
      :type:  int


   .. py:attribute:: status
      :type:  int


   .. py:attribute:: field_values
      :type:  list[FieldValue] | None


   .. py:property:: timestamp
      :type: datetime.datetime


      Provides a datetime for the archive event.

      This will lose information (the last few decimal places) since
      datetime does not handle nano seconds.

      :returns: datetime for event
      :rtype: datetime


   .. py:property:: pd_timestamp
      :type: pandas.Timestamp


      Provides a pandas Timestamp for the archive event.

      :returns: datetime for event
      :rtype: datetime


.. py:function:: year_timestamp(year: int) -> int

   Generates int timestamp for number of seconds from unix epoch at start of year.

   :param year: year
   :type year: int

   :returns: seconds from epoch of start of year.
   :rtype: int


.. py:function:: ysn_timestamp(year: int, seconds: int, nanos: int) -> pandas.Timestamp

   Get datetime from year, seconds into year and nanoseconds.

   :param year: year
   :type year: int
   :param seconds: seconds into year
   :type seconds: int
   :param nanos: nanoseconds
   :type nanos: int

   :returns: datetime
   :rtype: Timestamp


.. py:function:: dataframe_from_events(events: list[ArchiveEvent]) -> pandas.DataFrame

   Converts a list of ArchiveEvent to pd.DataFrame.

   :param events: input events
   :type events: list[ArchiveEvent]

   :returns:

             Output dataframe with columns "date", "val"
               where "date" is index column.
   :rtype: pd.DataFrame