Metric registry¶

A metric measures a finished run and draws as a level-less plot. Every metric registers here under a name; third-party metrics load through the ob_analytics.metrics entry-point group (see Extending). A registered value is a Metric instance — a metric needs no per-run construction, so the object registered is the object called.

The name is also the plot concept the metric draws under, so a renderer registered at (name, None, backend) is the metric's face. A registered metric shows up in available_concepts(), renders through result.plot(name), and gets its own gallery card — with no edit to ob-analytics.

Metrics run on demand, not during Pipeline.run: use PipelineResult.metric for one, PipelineResult.metrics() for every metric that applies to the run's resolution.

register_metric ¶

register_metric(metric: Metric) -> None

Register metric under its own :attr:~ob_analytics.protocols.Metric.name.

Case-insensitive; overwriting an existing registration is allowed (handy for tests and for a plug-in that intentionally shadows a built-in).

list_metrics ¶

list_metrics() -> list[str]

Return a sorted list of registered metric names.

get_metric ¶

get_metric(name: str) -> Metric

Return the metric registered under name (case-insensitive).

Raises:

Type	Description
`KeyError`	If no metric is registered under name; the message lists the registered names.

load_metric_plugins ¶

load_metric_plugins(*, force: bool = False) -> list[str]

Discover and register metrics advertised via entry points.

Scans the :data:ENTRY_POINT_GROUP entry-point group; each entry's value is loaded to a :class:~ob_analytics.protocols.Metric class, instantiated with no arguments, and registered under its own name. This is what lets a metric live in a separate installable package without editing ob-analytics.

Idempotent: the scan runs once per process unless force is set (the test suite forces a re-scan after monkeypatching the entry points). A plug-in that fails to import is logged and skipped, so one broken package cannot stop the rest from loading.

Returns:

Type	Description
`list of str`	The names newly registered by this call.