7f7e706d78ab968a1221c6179dfdba714860bd12 introduced the files() api and documented a importlib.abc.TraversableReader protocol, but it did not implement it.

This class is documented and marked as introduced in 3.9, but it's actually missing.

I don't believe a `TraversableReader` protocol was intended. Instead, the referenced change introduced the `TraversableResources` ABC. There's a typo in the docs. I created PR 26317 instead to correct the mistake. WDYT?

We do implement the protocol, and not TraversableResources, in some places, such as DegenerateFiles for eg. It seems to me that maybe that is an issue and we actually want to inherit from TraversableResources.

The question here is, are people supposed to be implementing readers with just files(), or are they always expected to inherit TraversableResources?

Regardless of the usefulness in code, please also consider type hinting. If people are expecting to be using this protocol, we should expose it.

> are people supposed to be implementing readers with just files(), or are they always expected to inherit TraversableResources?

A resource provider could potentially implement only the `files()` method (what I think you're calling `TraversableReader`), but my expectation was that all providers would provide a Reader derived from `TraversableResources` in order to provide backward-compatibility for the `ResourceReader` interface. Long term, I'd expect to deprecate all but `files()` on `TraversableResources`.

If a provider only implemented `files()` today and did not inherit from `TraversableResources`, they would still satisfy the `files()` API, but not the ResourceReader API (i.e. violate the expectation that `Loader.get_resource_reader` returns a ResourceReader).

I decided not to present both `TraversableReader` and `TraversableResources` as separate classes because the latter was sufficient for all known cases.

> It seems to me that maybe that is an issue and we actually want [DegenerateFiles] to inherit from TraversableResources.

Perhaps. What advantage would that have?

> Regardless of the usefulness in code, please also consider type hinting.

Agreed, there are some places where type hints would drastically improve readability.

> If people are expecting to be using this protocol, we should expose it.

My instinct is `TraversableResources` is the preferred protocol for now, although I think it's likely we'll want to separate out the TraversableReader when necessary. Let's plan to do that in importlib_resources first.

New changeset d309bcc9e36adb2437a02550514df3efeb1b2343 by Miss Islington (bot) in branch '3.10':
bpo-44195: Use 'TraversableResources' in the docs to match the implementation. (GH-26317)
https://github.com/python/cpython/commit/d309bcc9e36adb2437a02550514df3efeb1b2343

New changeset ab4da079232356e781743b2782148bc7c03f1ee3 by Miss Islington (bot) in branch '3.9':
[3.9] bpo-44195: Use 'TraversableResources' in the docs to match the implementation. (GH-26317) (GH-26335)
https://github.com/python/cpython/commit/ab4da079232356e781743b2782148bc7c03f1ee3