event-model

library1.23.1pypypi✓ verified 89d ago

Data model used by the bluesky ecosystem. Defines schemas for experimental data documents (e.g., Event, EventDescriptor, RunStart). Currently at version 1.23.1, released on a monthly cadence.

data serialization

pip install event-model

github ↗package ↗

INSTALL

IMPORT

SIG · EVENT-MODEL

event-model

datapythonv1.23.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Event

✓ from event_model import Event

✗ from event_model.schemas import Event

Event is exported from the top-level package, not from submodules

RunStart

✓ from event_model import RunStart

✗ from bluesky_models import RunStart

The correct package is event-model, not bluesky_models

EventDescriptor

✓ from event_model import EventDescriptor

✗ from bluesky import event_model

bluesky package does not re-export event-model types directly

Create and print basic event-model documents

from event_model import Event, RunStart start = RunStart( uid='abc123', time=1640000000.0, plan_name='scan', scan_id=42 ) event = Event( uid='def456', time=1640000001.0, descriptor_uid='ghi789', seq_num=1, data={'det': 3.14159}, timestamps={'det': 1640000001.0}, filled={} ) print(start, event)

Debug

Known issues

breakingIn v1.23, the internal representation changed from pydantic BaseModel to jsonschema + TypedDict. Code that relied on pydantic methods (e.g., .dict(), .copy()) will break. Use dict() and copy from the TypedDict protocol instead.

fix

Replace .dict() with dict(doc) and .copy() with dict(doc); avoid pydantic-specific features.

affects: >=1.23.0

breakingIn v1.21, StreamResource and StreamDatum schemas changed significantly: `path_semantics` and `resource_kwargs` removed; `uri`, `parameters`, and `mimetype` added.

fix

Update code that creates StreamResource/StreamDatum to use new fields; drop old fields.

affects: 1.21.0

gotchaIn v1.22.0, DataKey fields `precision`, `choices`, and `units` became required (non-optional). Leaving them out is still allowed, but providing None raises a validation error.

fix

Remove None values from those fields; omit the keys entirely if not needed.

affects: 1.22.0 - 1.22.2

Errors

Common errors & fixes

ImportError: cannot import name 'Event' from 'event_model.schemas'

Event is exported from the top-level event_model package, not from event_model.schemas.

fix

Use: from event_model import Event

AttributeError: 'Event' object has no attribute 'dict'

In v1.23, Event is a TypedDict, not a pydantic BaseModel. pydantic's .dict() is not available.

fix

Use: dict(event) or copy with dict(event)

ValidationError: 1 validation error for DataKey precision none is not an allowed value (type=type_error.none.not_allowed)

In v1.22.0+, DataKey fields like 'precision' cannot be None; omit the key if not needed.

fix

Remove the field or use a valid value.

Upgrade

Version history

1.23.1latest on PyPI · released Aug 28, 2025

Audit

Dependencies

jsonschemarequiredSchema validation; replaced pydantic in v1.23

numpyoptionalUsed for type definitions

pydanticoptionalPin <2.11 for Python 3.8 support

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/bluesky/event-model ↗

packagehttps://pypi.org/project/event-model/ ↗