Tasks¶

Tasks are normal Python functions that serve as processing steps inside Workflows.

To turn a Python function into a task, simply decorate it with @workflow.task:

In [ ]:

from laboneq import workflow


@workflow.task
def add(a, b):
    return a + b

from laboneq import workflow @workflow.task def add(a, b): return a + b

When used by themselves, Tasks behave like regular Python functions:

In [ ]:

add(1, 2)

add(1, 2)

When a Task is used inside a Workflow, its input and output parameters are stored in the result of the executed Workflow; check out the Workflow tutorial to see how this works.

The inputs and outputs of the Task are also saved to disk if a FolderStore has been configured; see the LogBook tutorial.

A Task can be configured to never have it's inputs and outputs saved to disk during the execution of a Workflow. This is done when the Task is created, using the save=False argument:

In [ ]:

@workflow.task(save=False)
def add(a, b):
    return a + b

@workflow.task(save=False) def add(a, b): return a + b

Note: When used inside a Workflow, a Task does not behave as a simple Python function anymore. Instead, it become an instance of a Reference class, which gets resolved to the Python function implemented by the Task only when the Workflow is executed. This is explained in more detail in the tutorial on the Workflow Syntax.

Ready-Made Tasks in LabOne Q¶

When running quantum-computing experiments with LabOne Q there are usually a few higher-level steps that one has to perform:

• Build an Experiment describing the pulse-sequence description of your measurement.
• Compile the Experiment.
• Run the Experiment.

LabOne Q provides ready-made Tasks for compiling and running Experiments, and for combining several Results into one single instance.

Let's have a look at the first two:

In [ ]:

from laboneq.workflow.tasks import compile_experiment, run_experiment

from laboneq.workflow.tasks import compile_experiment, run_experiment

Inspect the docstrings

In [ ]:

# docstring
compile_experiment?

# docstring compile_experiment?

In [ ]:

# docstring
run_experiment?

# docstring run_experiment?

Inspect the source code

In [ ]:

# source code
compile_experiment.src

# source code compile_experiment.src

In [ ]:

# source code
run_experiment.src

# source code run_experiment.src

Tasks for Building an Experiment¶

The Task for building an Experiment pulse sequence depends on the quantum experiment that is being created.

In LabOne Q, we call these tasks create_experiment. You can find our implementations of such tasks for many common quantum-computing experiments in the LabOne Q Applications Library. Check them out!

Why have tasks at all?¶

Using Tasks and Workflows comes with many advantages:

• Being able to produce a well-organised experiment record when tasks are used in workflows; see here.
• Being able to supply options to tasks in a structured way.
• Being able to recover partial results when errors occur.
• Being able to pause and resume workflow execution.
• Being able to build complex dynamic workflows that can execute tasks conditionally or run tasks in loops.