Bluesky

1.15.0 verified Fri May 01 auth: no python

Bluesky is a Python library for experiment specification and orchestration, providing a run engine (RunEngine) that coordinates data acquisition plans, detectors, and flyers. It is part of the broader Bluesky ecosystem for synchrotron and laboratory data acquisition. Current version 1.15.0 (requires Python >=3.10). Releases roughly quarterly, with a focus on stability and performance improvements.

pip install bluesky

Common errors

error TypeError: __init__() got an unexpected keyword argument 'plan' ↓

cause Passing a plan to RE() incorrectly; RE expects a plan as the first argument, but user tried `RE(plan=my_plan)`.

fix

Call RE(my_plan) instead of RE(plan=my_plan).

error AttributeError: module 'bluesky' has no attribute 'RunEngine' ↓

cause Incorrect import or older bluesky version (<0.10) where RunEngine was in a different location.

fix

Ensure bluesky>=0.10 and use from bluesky import RunEngine.

error ValueError: The truth value of an array with more than one element is ambiguous ↓

cause Passing a numpy array where a scalar is expected, e.g., as a motor setpoint in a plan.

fix

Ensure setpoints are scalars (float/int) and not arrays; use float(value) if necessary.

Warnings

breaking In v1.14.0, `Movable.set` arguments changed: previously positional, now only keyword arguments are accepted. ↓

fix Update any custom device `set` methods to accept `**kwargs` and pass values as keyword arguments.

deprecated `bluesky.plans.inner_product` and other 'inner' plans are deprecated; use the 'outer' plan wrappers. ↓

fix Replace `count([det])` with `count([det])` (outer plan) – they are directly callable.

gotcha The RunEngine is a singleton per process. Creating multiple RE instances can lead to unexpected behavior. ↓

fix Use a single global RE instance; avoid re-instantiation.

gotcha Subscriptions via `RE.subscribe` must be set before the plan is executed; late subscriptions may miss events. ↓

fix Call `RE.subscribe(callback)` before `RE(plan)`.

Install

conda install -c conda-forge bluesky

Imports

RunEngine

wrong

from bluesky.run_engine import RunEngine

correct

from bluesky import RunEngine

RunEngine is at the top-level, not in a submodule.

Plan
wrong
```
from bluesky.plan import bp
```
correct
```
from bluesky import plan as bp
```
The standard convention is to import the 'plans' module as 'bp'.
Msgen
wrong
```
from bluesky.message import Msg
```
correct
```
from bluesky import msg
```
Message objects are accessed via `bluesky.msg.Msg`, not a separate message module.

Quickstart

Instantiates a RunEngine, defines a dummy detector (callable returning a dict), and executes a count plan with a live table callback.

from bluesky import RunEngine
from bluesky.plans import count
from bluesky.callbacks import LiveTable

RE = RunEngine()
def detector():
    return {'det': 1}
RE(count([detector()])