Hey are there any better way of dealing with pylint error or should I just disable these lints: When using DynamicOut:

some_op().map(another_op)

E1101: Generator 'generator' has no 'map' member (no-member)

And using context in ops:

No value for argument 'context' in function call (no-value-for-parameter)

Hi Tadas, just letting you know I'm looking into this.

@sean thanks!

hi @sean were you able to find an answer? I googled around and found these older related threads. https://github.com/dagster-io/dagster/issues/1720 https://github.com/PyCQA/pylint/pull/2926 It seems like it is currently implemented as

signature_mutator

instead of

function_mutator

. But also, what I took away from this thread is that if the decorator is properly annotated, this wouldn't be an issue https://github.com/microsoft/pyright/issues/660

@sean did you had an opportunity to check this?

Hi Tadas and Stanely, my aploogies for the long wait on this. I just looked into this and here are my conclusions/recommendations: • Pylint’s typechecking functionality is pretty basic and struggles with the kind of logic we use for op composition. • The only pylint-based workaround is the

--signature-mutators

option for the

typecheck

checker. In theory this just makes functions decorated by the target opaque to pylint, so pylint won’t typecheck e.g. the return value. So adding

dagster.op

to pylint’s

signature-mutators

should fix the problem in OP. • That said, I was unable to get it to work-- I included this in a

pyproject.toml

but continued to see the original problem:

[tool.pylint.typecheck]
signature-mutators = ['dagster.op']

• In any case, it doesn’t really matter because unfortunately, there is no way for us as library developers to make sure

signature-mutators

is set on the user end for functions in our library-- basically

signature-mutators

is part of

pylint

configuration, and we can’t control user

pylint

configuration. The only way we as developers have to communicate with the user’s

pylint

is by appropriately annotating our decorators, but in this case I believe we’ve done that but

pylint

does not account for it. Given this, there are two possible solutions: • *RECOMMENDED: Disable the pylint

typecheck

checker. * This checker is redundant with mypy and/or pyright anyway, both of which understand Dagster’s annotations and do not raise an error for OP. • *ALTERNATIVE: Configure pylint

signature-mutators

on the user end to exclude

op

. * @Stanley Yang the thread you linked is for pyright, and it’s correct that Pyright won’t raise errors for properly annotated functions, but that doesn’t seem to be true of pylint. Please let me know if I’ve missed something here or you have more information!

thanks @sean! that makes sense and we will try it out

@sean thanks!

[tool.pylint.typecheck]
signature-mutators = ['op']

I added this snippet to my pyproject.toml and it worked 🙂 But it only solves part of the problem. I’m still getting:

E1101: Generator 'generator' has no 'map' member (no-member)

for code using DynamicOut:

some_op().map(another_op)

Tadas yeah that’s the behavior I tested, which adding signature mutators did not fix. I guess I had pylint configured correctly. It appears that in this case, signature-mutators just doesn’t work. I can only recommend you follow either (1) take it up with

pylint

, this might be a bug-- it seems like

signature-mutators

should disable

no-member

checks; or (b) disable the pylint

typecheck

checker and use

mypy

or

pyright

instead. Sorry I don’t have a better solution.

I’ve modified my config like this:

[tool.pylint.typecheck]
generated-members = ["map"]
signature-mutators = ["op"]

Lets say map is a generated-member 🙂