An open issue in PEP 302 is whether to require __loader__ attributes on modules. The claimed worry is memory consumption, but considering importlib and zipimport are already doing this that seems like a red herring. Requiring it, though, opens the door to people relying on its existence and thus starting to do things like loading assets with ``__loader__.get_data(path_to_internal_package_file)`` which allows code to not care how modules are stored (e.g. zip file, sqlite database, etc.).<div>
<br></div><div><div>What I would like to do is update the PEP to state that loaders are expected to set __loader__. Now importlib will get updated to do that implicitly so external code can expect it post-import, but requiring loaders to set it would mean that code executed during import can rely on it as well.</div>
</div><div><br>As for __package__, PEP 366 states that modules should set it but it isn't referenced by PEP 302. What I want to do is add a reference and make it required like __loader__. Importlib already sets it implicitly post-import, but once again it would be nice to do this pre-import.</div>
<div><br></div><div>To help facilitate both new requirements, I would update the importlib.util.module_for_loader decorator to set both on a module that doesn't have them before passing the module down to the decorated method. That way people already using the decorator don't have to worry about anything and it is one less detail to have to worry about. I would also update the docs on importlib.util.set_package and importlib.util.set_loader to suggest people use importlib.util.module_for_loader and only use the other two decorators for backwards-compatibility.</div>