Doubt about Absolute import vs relative import

[skoudoro]

Hi all,

Our package is using absolute import (fury: https://github.com/fury-gl/fury).

We just added lazy-loader package and it seems to work like a charm.

However, when we activate EAGER_IMPORT on our CI's or locally, we encounter many circular import and everything fails.

Not sure why and it seems I miss understand something.

Can someone explain this behavior?

I check all the other projects using lazy-loader package and they all use relative import. So, I suppose, there is a reason I do not get or an issue with the package.

Thank you for the feedback

[stefanv]

I'm away atm but please ping me if you don't hear back by mid-August.

[Erotemic]

I don't think this has anything to do with absolute vs relative imports. It looks like a problem with how EAGER_IMPORT was designed. When EAGER_IMPORT is truthy, it runs these lines inside the attach function:

    if os.environ.get("EAGER_IMPORT", ""):
        for attr in set(attr_to_modules.keys()) | submodules:
            __getattr__(attr)

which means that when this is called __getattr__ is not defined on the top level of the module, so any lazy attribute that attempts to re-access a top-level attribute will reference the base module before it's __getattr__ is defined, and thus not be able access the lazy variables.

The reason I've never run into this is that I don't think I typically write code where simply accessing an attribute will access another attribute in the module. But thinking about it, I'm not immediately sure what the pattern looks like that would cause that. Are you using any custom __getattr__ logic outside of what is done via lazy-loader? It could be that nested attach_stubs could cause this issue, but I don't immediately see the problem. It might be some interaction with the attatch_stub file.

[skoudoro]

Thank you for the explanation @Erotemic. At some point I need to create a minimal example to understand in details what is going on.

Are you using any custom getattr logic outside of what is done via lazy-loader?

No