Feature/instance level source customization

[acederberg]

I have made this pull request to close my own issue, #346.

I essentially wanted instance level source customization, therefore I added the callback to _settings_customize_instance.

This change should also help users when testing since they will not have to add settings_customize_sources to their class, and will only have to pass _settings_customize_instance to the constructor.

This also includes a small modification to pyproject.toml to define test dependencies to improve the developer experience.

Sorry that black went wild on settings.py, there are only 3 lines actually added in there. I am assuming that actions will probably fix this, if not, I will fix it.

[hramezani]

Thanks @acederberg for this PR. please:

• Revert unrelated code formatting changes to make lint happy and also make the PR easier to review
• Add some tests for the change
• Document how to use the new feature in https://docs.pydantic.dev/latest/concepts/pydantic_settings/#customise-settings-sources

[acederberg]

@hramezani I added tests and docs, it looks like everything is good to go. I notice that the tests fail for 3.8 because of the use of tuple type hints - yet such type hints are included in the source. I will fix this so that tests pass but am concerned about this inconsistency.

[acederberg]

@hramezani This should work. Is there anything else I ought to do?

[hramezani]

Thanks @acederberg for the update.

I need to check it more with the team. not sure this is the best way to support it.

[hramezani]

@acederberg Unfortunately, we are going not to accept this PR because:

• Supporting instance-level source customization needs some structural work that I prefer to do it in V3
• This is a specific use case and adding a new param does not make sense here. I know that pydantic-settings basically doesn't support it, but it doesn't make sense to add a new param now and probably remove it in V3

I think we can keep the issue open to think about it in V3

Thanks for your effort here and sorry for this

[acederberg]

@hramezani No worries, I understand - these are good reasons.

Is there any way that I could help with v3?

[hramezani]

@hramezani No worries, I understand - these are good reasons.

Is there any way that I could help with v3?

Thanks for your understanding ❤️

Right now, we don't have any specific plan for V3. but we can keep the issue open and V3 tag to it to consider it when we are going to work on V3.

I am going to close the PR.

Thanks for your effort