Quick question - if I have a set of tasks that don...
# ask-communityj
Jason Boorn
10/27/2021, 4:08 PMQuick question - if I have a set of tasks that don't depend on each other but that I want to run serially, what's the correct way to do that?
a
Anna Geller
10/27/2021, 4:25 PM
If you want to ensure that one task runs after another in a specific order, then you need to set upstream or downstream dependencies, as shown here:
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from prefect import task, Flow
@task(log_stdout=True)
def hello_world():
print("hello world")
@task(log_stdout=True)
def hello_world_2():
print("hello world")
with Flow("basic-flow") as flow:
t1 = hello_world()
t2 = hello_world_2()
t1.set_downstream(t2)
if __name__ == "__main__":
flow.visualize()Anna Geller
10/27/2021, 4:27 PM
but if the order is not important to you, you can just pass the list of tasks:
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from prefect import task, Flow
@task(log_stdout=True)
def hello_world():
print("hello world")
@task(log_stdout=True)
def hello_world_2():
print("hello world")
flow = Flow("basic-flow", tasks=[hello_world, hello_world_2])
if __name__ == "__main__":
flow.visualize()j
Jason Boorn
10/27/2021, 4:30 PMYup thats perfect - thanks
k
Kevin Kho
10/27/2021, 5:31 PM
I just wanna add another syntax:
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with Flow("basic-flow") as flow:
t1 = hello_world()
t2 = hello_world_2(upstream_tasks=[t1])👍 1
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