multiple inheritance: changed MRO about pydantic-settings HOT 2 CLOSED

@ergleb78 BaseSettings inherits BaseModel and the core functionality of BaseModel is that if you inherit parent BaseModel, it will mutate child class and set attributes of parent class.

from pydantic import BaseSettings


class ConfigBase(BaseSettings):
    p1: str = None


class AppConfig(ConfigBase):
    p2: str = "AppConfig"


class AWSConfigBase(ConfigBase):
    p1: str = "AwsConfigBase"


class Config(AppConfig, AWSConfigBase):
    pass

# When you check AppConfig class attributes
print(AppConfig().__dict__)
>>> {'p1': None, 'p2': 'AppConfig'}

So if you go by MRO, so Config().p1 is search in AppConfig and yes, there is attribute p1 exists so it will return its value, None.

So this issue does not changes MRO, its the core functionality of pydantic BaseModel which adds the attributes to inherited classes.
@samuelcolvin please verify this.

from pydantic-settings.

As @soamicharan mentioned it is by design in pydantic. you can get different values by changing the

class Config(AppConfig, AWSConfigBase):

to

class Config(AWSConfigBase, AppConfig):

from pydantic-settings.