How to develop a Worker Program in Python

To develop a Worker, use the Worker() constructor and add your Client, Task Queue, Workflows, and Activities as arguments.

The following code example creates a Worker that polls for tasks from the Task Queue and executes the Workflow.

worker = Worker(
    client,
    task_queue="your-task-queue",
    workflows=[YourWorkflow],
    activities=[your_activity],
)

The following code example shows a Worker hosting Workflows and Activities.

async def run_worker(stop_event: asyncio.Event):
    # Create Client connected to server at the given address
    client = await Client.connect("127.0.0.1:7233", namespace="your-custom-namespace")

    # Run the worker until the event is set
    worker = Worker(
        client,
        task_queue="your-task-queue",
        workflows=[YourWorkflow],
        activities=[your_activity],
    )
    async with worker:
        await stop_event.wait()

The asyncio.Event that will be set when the Worker should stop. Although this example accepts a stop event and uses async with, you can also use run() and shutdown(). The shutdown() operation waits on all Activities to complete, so if a long-running Activity does not at least respect cancellation, the shutdown might never complete.