epicsarchiver.retrieval.archive_event

Archive Event module for the ArchiveEvent class.

Classes

`FieldValue`	Basic representation of a changed field value from an archive event.
`ArchiveEvent`	One Event, retrieved from the AA, representing a change in value of a PV.

Functions

`year_timestamp`(→ int)	Generates int timestamp for number of seconds from unix epoch at start of year.
`ysn_timestamp`(→ pandas.Timestamp)	Get datetime from year, seconds into year and nanoseconds.
`dataframe_from_events`(→ pandas.DataFrame)	Converts a list of ArchiveEvent to pd.DataFrame.

Module Contents

class epicsarchiver.retrieval.archive_event.FieldValue[source]

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

Returns:: Pair of name and value
Return type:: FieldValue

name: str | None[source]

value: str | None[source]

class epicsarchiver.retrieval.archive_event.ArchiveEvent[source]

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

pv: str[source]

val: int | float | str | list[str] | list[int] | list[float] | bytes[source]

secondsintoyear: int[source]

year: int[source]

nanos: int[source]

severity: int[source]

status: int[source]

field_values: list[FieldValue] | None[source]

property timestamp: datetime.datetime[source]

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
Return type:: datetime

property pd_timestamp: pandas.Timestamp[source]

Provides a pandas Timestamp for the archive event.

Returns:: datetime for event
Return type:: datetime

epicsarchiver.retrieval.archive_event.year_timestamp(year: int) → int[source]

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

Parameters:: year (int) – year
Returns:: seconds from epoch of start of year.
Return type:: int

epicsarchiver.retrieval.archive_event.ysn_timestamp(year: int, seconds: int, nanos: int) → pandas.Timestamp[source]

Get datetime from year, seconds into year and nanoseconds.

Parameters:

year (int) – year
seconds (int) – seconds into year
nanos (int) – nanoseconds

Returns:

datetime

Return type:

Timestamp

epicsarchiver.retrieval.archive_event.dataframe_from_events(events: list[ArchiveEvent]) → pandas.DataFrame[source]

Converts a list of ArchiveEvent to pd.DataFrame.

Parameters:

events (list[ArchiveEvent]) – input events

Returns:

Output dataframe with columns “date”, “val”: where “date” is index column.

Return type:

pd.DataFrame