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Version: Python

LivenessScope

LivenessScope is a Python class that manages the reference counting of tables and other query resources that are created within it.

Syntax​

scope = LivenessScope()

Parameters​

None.

Returns​

An instance of a LivenessScope class.

Examples​

The following example uses function generated tables to produce a blink table with 5 new rows per second. Encapsulating the function generated table inside of a liveness scope enables the safe deletion of data once the scope has been released. table_from_func will continue to tick after the scope is released until all referents have been deleted. That includes the ticking table in the UI.

from deephaven.liveness_scope import liveness_scope, LivenessScope
from deephaven import function_generated_table, empty_table


def random_data():
    return empty_table(5).update(
        ["X = randomInt(0, 10)", "Y = randomDouble(-50.0, 50.0)"]
    )


scope = LivenessScope()

with scope.open():
    table_from_func = function_generated_table(
        table_generator=random_data, refresh_interval_ms=1000
    )

# After a while...
del table_from_func
scope.release()