python: Use deterministic import

[Venefilyn]

Adds explicit imports and __all__ to __init__.py to explicitly
mention the methods available to use upon importing the pixelmatch
library.

Signed-off-by: Freya Gustavsson freya@venefilyn.se

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[whtsky]

Could you please elaborate on the reason for this change?

[Venefilyn]

Could you please elaborate on the reason for this change?

I ran into F405 on Ruff when vendoring it in Cockpit for wildcard import. And then F401 on Ruff for re-exporting. Both made sense to me

[whtsky]

Thanks for clarifying. The current __init__.py intentionally re-exports all public names from core and utils. If there's anything we don't want export, we'd prefix it with _ to follow the Python convention to mark it as private.
Given that, manually listing all exports feels like adding an extra source of truth. I'm not sure there's much practical benefit from it.
While I understand this change do make Ruff happy, I don't think F405&F401 really fit in this case. I feel it may be better handled downstream by excluding/ignoring the vendored package, or adding a targeted ignore for these rules.