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F821 on use of Literal with strings, e.g. Literal['foo'] #128
Description
Since #119 was fixed via #125, I tried ruff again (build from main) with pydantic.
I get a few remaining F821 errors due to use of strings in Literal, the line numbers are also incorrect - seems to always be 1.
From this code (and some other places in that file), I get:
pydantic/config.py:1:1: F821 Undefined name `deep`
pydantic/config.py:1:1: F821 Undefined name `none`
pydantic/config.py:1:1: F821 Undefined name `deep`
pydantic/config.py:1:1: F821 Undefined name `shallow`
pydantic/config.py:1:1: F821 Undefined name `before_validation`
pydantic/config.py:1:1: F821 Undefined name `after_validation`
pydantic/config.py:1:1: F821 Undefined name `none`
pydantic/config.py:1:1: F821 Undefined name `shallow`
pydantic/config.py:1:1: F821 Undefined name `before_validation`
pydantic/config.py:1:1: F821 Undefined name `after_validation`
Example code:
copy_on_model_validation: Literal['none', 'deep', 'shallow']
post_init_call: Literal['before_validation', 'after_validation']
Activity
samuelcolvin commentedon Sep 8, 2022
I have no idea how you differentiate in a general way between the following:
Obviously you can whitelist
Literal, but I have no idea how you would work out whetherCustomThingis parameterised with strings or types which might be strings.I guess you have to assume it's parameterised with types, can maybe one day allow a magic comment or magic property which tells ruff that
CustomThingis parameterised with literals - maybe there's a pep for this, but I don't know of it.charliermarsh commentedon Sep 8, 2022
Yeah it looks like PyFlakes special-cases
Literal: https://github.com/PyCQA/pyflakes/blob/master/pyflakes/checker.py#L1464. Will fix.PyFlakes actually has a lot of custom logic for caching forward-reference annotation in
castandTypeVarcalls which we're yet to handle, so this may pop up there too.charliermarsh commentedon Sep 8, 2022
(The
1:1issue will be handled separately, tracking in #132. Thank you!)vianmixtkz commentedon Apr 4, 2023
I still have the same issue
What version of ruff fixes it ?
I am using ruff==0.0.254
charliermarsh commentedon Apr 4, 2023
@vianmixtkz - This was fixed long long ago. How are you importing
Literal?vianmixtkz commentedon Apr 4, 2023
Gotcha,
I was importing it from another module. I tried to import it directly from typing and it fixed the issue.
Thanks.
What caused that though ?
charliermarsh commentedon Apr 4, 2023
If you add that module to
typing-modules, that should fix the issue for you without having to import fromtypingdirectly. We don't trace imports across files, so if you importLiteralin one file, export it, and then import that export elsewhere, we don't know that it's equivalent totyping.Literal. By adding your first-party module totyping-modules, you can tell Ruff that anything imported from that module should be considered equivalent to atypingimport.