Hello, World!

Tags: Basic

Let’s write a Flyte workflow() that invokes a task() to generate the output “Hello, World!”.

Flyte tasks are the core building blocks of larger, more complex workflows. Workflows compose multiple tasks – or other workflows – into meaningful steps of computation to produce some useful set of outputs or outcomes.

To begin, import task and workflow from the flytekit library.

from flytekit import task, workflow

Define a task that produces the string “Hello, World!”. Simply using the @task decorator to annotate the Python function.

@task
def say_hello() -> str:
    return "Hello, World!"

You can handle the output of a task in the same way you would with a regular Python function. Store the output in a variable and use it as a return value for a Flyte workflow.

@workflow
def hello_world_wf() -> str:
    res = say_hello()
    return res

Run the workflow by simply calling it like a Python function.

if __name__ == "__main__":
    print(f"Running hello_world_wf() {hello_world_wf()}")

Next, let’s delve into the specifics of tasks, workflows and launch plans.