[Bug] Filtering models by tags using ModelFilter doesn't work

[Wauplin]

Originally reported by @thomwolf on Slack (private):

Model filtering by tags using ModelFilter doesn't work:

>>> from huggingface_hub import list_models, ModelFilter

>>> filter = ModelFilter(author="HuggingFaceBR4", tags=["tensorboard"])
>>> models = list(list_models(filter=filter))
>>> models[0]   # <= doesn't have a "tensorboard" tag
ModelInfo: { 
  {'_id': '63ff7c00ea1782e758c69b5d',
   'author': 'HuggingFaceBR4',
   'id': 'HuggingFaceBR4/gpt2-20b',
   (...)
   'tags': ['transformers', 'gpt2', 'text-generation', 'text-generation-inference', 'region:us']}
}

A workaround is to use list_models(author="HuggingFaceBR4", filter="tensorboard") directly without ModelFilter. Would still be good to investigate.

[martinbrose]

I shouldn't have closed my PR. @Wauplin, could you please reopen it?

The problem here is that the /api/models GET endpoint does not seem to have an additional parameter for tags.
It needs to be provided as part of the "filter" parameter, similar to the language filter, which is also just a language code within ModelInfo.tags. The original code erroneously provided the tags within ModelFilter as a "tags" parameter to the API endpoint.

[Wauplin]

Hi @martinbrose, thanks for investigating the bug and finding the cause! So this means the tags filter most probably never worked before 😬 I re-opened the PR you've created and will have a look at it soon.

[martinbrose]

Yes, seems to have never worked. There also wasn't a test case for it.

On the other hand, not many people seem to have complained about it. So maybe this functionality isn't really used anyway.

[Wauplin]

So maybe this functionality isn't really used anyway.

I think this is the key take-away! I've created #1676 to definitely deprecate/remove those. We still need to find a way to do it without breaking too much stuff but it's definitely the direction we want to take.