Latest values
Each telemetry stream stores the latest value received on it if "Persist last known value" is toggled on for the stream in Settings->Streams.
It's possible to retrieve the latest value without having to know the time range of when it was ingested by using the query_stream_current_value method.
Example script of querying for the latest value of a stream
from formant.sdk.cloud.v1 import Client as FormantClient
if __name__ == "__main__":
# to authenticate set FORMANT_EMAIL and FORMANT_PASSWORD
# environment variables for an existing service account
fclient = FormantClient()
device_id = "572f5ff3-63e9-4687-b242-c0d8a4891d80"
# query last known value of all streams from a device
# within a given period
query_result = fclient.query_stream_current_value(
{
"start": "2021-01-01T00:00:00.000Z",
"end": "2021-01-10T00:00:00.000Z",
"deviceIds": [device_id],
}
)
print(query_result)
# query last known value of all streams matching a name
query_result = fclient.query_stream_current_value(
{
"names": ["engine_temp"],
}
)
# query last known value of all streams matching a tag
query_result = fclient.query_stream_current_value(
{
"tags": {"location": ["sf"]},
}
)