You can access the MetricRegistry:
Which is a class directly from a third party library.
You could ask it for the set of gauges it contains, which will return a dictionary:
The Guage object you get from that dictionary (at the ClockDriftDetector.driftGauge key) will have a getValue method: Gauge - metrics-core 4.0.3 javadoc
So it would look something like:
from com.inductiveautomation.ignition.gateway import IgnitionGateway
__gateway = IgnitionGateway.get()
__metrics = __gateway.metricRegistry
__driftGauge = __metrics.gauges["ClockDriftDetector.driftGauge"]
def getDriftValue():
return __driftGauge.value