I am doing a very simple example, but keep getting the message `AttributeError: 'Flow' object has no...

David Maier

10/09/2023, 2:45 PM

I am doing a very simple example, but keep getting the message

AttributeError: 'Flow' object has no attribute 'serve'

alex

10/09/2023, 2:47 PM

Hey @David Maier! What version of

prefect

do you have installed? Sharing the output of

prefect version

would be great!

David Maier

10/09/2023, 2:48 PM

Copy code

Version:             2.82
API version:         0.8.4
Python version:      3.9.14
Git commit:          afbed19d
Built:               Fri, Feb 17, 2023 10:02 AM
OS/Arch:             darwin/arm64
Profile:             default
Server type:         cloud

David Maier

10/09/2023, 2:48 PM

Whereby the Prefect version in my deps file is

prefect = "^2.13"

David Maier

10/09/2023, 2:49 PM

Copy code

python = ">=3.9,<3.11"
requests = "^2.27.1"
prefect = "^2.13"
prefect-dask = "^0.2.5"
redis = "^4.1.1"
cleo = "^0.8.1"
boto = "^2.49.0"
boto3 = "^1.22.4"
scipy = "^1.8.1"
plotly-express = "0.4.0"
kaleido = "0.2.1"
markdown = "3.3.7"
sendgrid = "6.9.7"
pydantic = "<2.0.0"

alex

10/09/2023, 2:49 PM

Thanks! Are you using

poetry

? I remember seeing another user that used

poetry

that had a similar issue and a similar

prefect version

output.

David Maier

10/09/2023, 2:53 PM

Yes, but it shouldn’t make any difference, right? It just installs the deps to a virtualenv.

alex

10/09/2023, 2:57 PM

The most recent version of

prefect

2.13.5

, but

poetry

installed a version that is nearly eight months old, which is why

.serve

isn’t working for you.

David Maier

10/09/2023, 2:57 PM

BTW: Maybe unrelated. I realized that I had to pin the

pydantic

version because the CLI would otherwise not work as expected. It seems that at least one of my other dependencies does refer to a newer version because I didn’t have

pydantic

listed as an explicit dependency before.

David Maier

10/09/2023, 2:57 PM

OK, so let me try with 2.13.5 then

alex

10/09/2023, 2:58 PM

Ah, if you pinned

pydantic

then that might cause this behavior. Can you share the error that you saw from the CLI?

David Maier

10/09/2023, 3:10 PM

ImportError: cannot import name 'SecretField' from 'pydantic'

David Maier

10/09/2023, 3:11 PM

I am updating to

2.13.5

now and also removed the hardcoded

pydantic

version from my Poetry environment … so fingers crossed.

alex

10/09/2023, 8:23 PM

Just for reference, what version of

poetry

are you using?

David Maier

10/10/2023, 8:06 AM

OK, it seems to work now. I am right now upgrading an older Prefect 1.x project to 2.x and had to do a bunch of things to get it working:

David Maier

10/10/2023, 8:07 AM

1. I am now using version 2.13.5 of Prefect

David Maier

10/10/2023, 8:08 AM

2. The Poetry version was also outdated. I was on 1.1 which caused that

poetry update

ended up in an endless loop 🤷, so I am now using Poetry 1.6.1.

✅ 1

David Maier

10/10/2023, 8:08 AM

The

serve

function works now as expected. Thanks!

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🎉 1

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