mypy complains about settings object

[sr-verde]

Initial Checks

• I confirm that I'm using Pydantic V2 installed directly from the main branch, or equivalent

Description

Mypy complains about my settings object.

$ mypy pydampy
pydampy/config.py:3: error: Cannot find implementation or library stub for module named "pydantic_settings"  [import]
pydampy/config.py:3: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
pydampy/config.py:6: error: Class cannot subclass "BaseSettings" (has type "Any")  [misc]
pydampy/config.py:8: error: "object" not callable  [operator]
Found 3 errors in 1 file (checked 1 source file)

This error only occurs in strict mode:

pydampy/config.py:6: error: Class cannot subclass "BaseSettings" (has type "Any")  [misc]

Example Code

I have a simple config class like this one:


from typing import Literal
from pydantic import SettingsConfigDict
from pydantic_settings import BaseSettings


class Config(BaseSettings):
    log_level: Literal["NOTSET", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] = "WARNING"
    model_config = SettingsConfigDict(env_file=".env")


This is my `mypy.ini`:

```ini
[mypy]
plugins = pydantic.mypy
strict = true

follow_imports = silent
warn_redundant_casts = True
warn_unused_ignores = True
disallow_any_generics = True
check_untyped_defs = True
no_implicit_reexport = True

# for strict mypy: (this is the tricky one :-))
disallow_untyped_defs = True

[pydantic-mypy]
init_forbid_extra = True
init_typed = True
warn_required_dynamic_aliases = True

Python, Pydantic & OS Version

pydantic version: 2.0.1
        pydantic-core version: 2.0.2 release build profile
                 install path: /home/user/git/minimals/pydantic2-mypy/venv/lib/python3.11/site-packages/pydantic
               python version: 3.11.3 (main, Jun  5 2023, 09:32:32) [GCC 13.1.1 20230429]
                     platform: Linux-6.4.1-arch2-1-x86_64-with-glibc2.37
     optional deps. installed: ['typing-extensions']

$ pip list
Package           Version
----------------- -------
annotated-types   0.5.0
mypy              1.4.1
mypy-extensions   1.0.0
pip               22.3.1
pydantic          2.0.1
pydantic_core     2.0.2
setuptools        65.5.0
typing_extensions 4.7.1

Selected Assignee: @hramezani

Selected Assignee: @dmontagu

[hramezani]

Thanks @sr-verde for reporting this issue 🙏

You've imported SettingsConfigDict from pydantic and I think this is wrong. you have to import it from pydantic_settings.

I've tested your provided example by changing the import and it looks fine:

from typing import Literal
from pydantic_settings import BaseSettings, SettingsConfigDict


class Config(BaseSettings):
    log_level: Literal["NOTSET", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] = "WARNING"
    model_config = SettingsConfigDict(env_file=".env")

Could you please try it?

[sr-verde]

Yes, that solves the issue. And I know how it happened. Seems to be a bug in bump-pydantic.

I had this config in Pydantic v1:

from typing import Literal
from pydantic import BaseSettings


class Config(BaseSettings):
    log_level: Literal["NOTSET", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] = "WARNING"

    class Config:
        env_file = ".env"

Then, I executed dump-pydantic and got the following config file:

from typing import Literal
from pydantic import ConfigDict
from pydantic_settings import BaseSettings


class Config(BaseSettings):
    log_level: Literal["NOTSET", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"] = "WARNING"
    model_config = ConfigDict(env_file=".env")

As one can see bump-pydantic imported ConfigDict from pydantic instead from pydantic_settings.

[hramezani]

Thanks for the clarification.

It would be great to open an issue in bump-pydantic

[sr-verde]

Thanks for your help!

pydantic/bump-pydantic#52

[sr-verde]

Hey, sorry, need to reopen that issue again. Using strict mode in mypy this error still occurs:

pydampy/config.py:6: error: Class cannot subclass "BaseSettings" (has type "Any")  [misc]

[hramezani]

Could you install pydantic-settings from the main branch and test it?

I couldn't see the error by the mypy config you provided.

[sr-verde]

Yes, seems to be fixed in main branch. So I’ll wait for the next release. Sorry to interrupt you again.

[hramezani]

No worries. new release will come probably today.