env_prefix prevents env_file from working

[red8888]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

Assuming this is a bug because I found nothing in the docs explaining this behavior.

Spent forever trying to understand why env_file wasn't working. Commenting out env_prefix cause env_file to start working. This can't be by design right? I should be able to define both.

Example Code

model_config = SettingsConfigDict(
        env_file=[
            "my.env",
        ],
        # When uncommented pydantic does not attempt to load any files defined in env_file 
        # env_prefix="my_app_",
    )

Python, Pydantic & OS Version

pydantic version: 2.5.3
        pydantic-core version: 2.14.6
          pydantic-core build: profile=release pgo=true
                 install path: /usr/local/lib/python3.12/site-packages/pydantic
               python version: 3.12.1 (main, Dec 19 2023, 20:23:36) [GCC 10.2.1 20210110]
                     platform: Linux-6.5.11-linuxkit-x86_64-with-glibc2.31
             related packages: pydantic-settings-2.1.0 mypy-1.8.0 typing_extensions-4.9.0

Edit

I found the issue. The issue is that setting env_prefix causes pydantic to ignore non-prefixed env vars defined in you dotenv files.

I was expecting it to fail because I had un-prefixed vars defined in mysettings.env for example:

MY_SETTING_ONE=ksjdlksjd
MY_SETTING_TWO=zzzzzzz

Changing those to this worked:

MY_APP_MY_SETTING_ONE=ksjdlksjd
MY_APP_MY_SETTING_TWO=zzzzzzz

So I think the bug is pydantic should not be ignoring un-prefixed fields in dotenv files.

Because while this correctly throws Extra inputs are not permitted:

MY_APP_SETTING_THAT_DOESNT_EXIST=ksjdlksjd

This throws no errors at all:

SETTING_THAT_DOESNT_EXIST=ksjdlksjd

[hramezani]

Thanks @red8888 for reporting this.

Agree, that is probably a bug.

[kjithin]

Hi @hramezani
I'm interested in taking on this task. Given my limited experience in open source, I may require your assistance and guidance to successfully complete it. Would you consider assigning this issue to me?

[hramezani]

Thanks @kjithin, I've assigned it to you!

[kjithin]

Thanks @hramezani. I've submitted a pull request addressing this issue. Kindly review and share your feedback.