What is the default TaskRunner (executor)?

Prefect 2.0

SequentialTaskRunner is the default mechanism for sequential task execution. Here is how you can explicitly attach a task runner to your flow:

from prefect.task_runners import SequentialTaskRunner

@flow(task_runner=SequentialTaskRunner())

Prefect 1.0

The local executor is the default mechanism to make tasks run sequentially. The syntax:

from prefect.executors import LocalExecutor

flow.executor = LocalExecutor()