Define errors in errors.py

[Y4suyuki]

Define errors in utils except utils/_errors.py in errors.py

#2069

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[Y4suyuki]

@Wauplin Hi, I made another PR for defining errors.
I put errors in utils/_errors.py aside for this PR since they seem a bit complex so I just defined simpler errors in this PR.
Also I thought importing errors in utils/__init__.py seems redundant after defined them in errors.py and tried to remove them but I noticed that will change API of this library so I didn't include those changes in this PR.

[Wauplin]

Thanks for the contribution and explanations @Y4suyuki! Your reasoning looks good. I'll have a look at your PR next week and let you know :) In the meantime, have a great weekend 🤗

[Wauplin]

Thanks @Y4suyuki! I played with it a bit and it's definitely much cleaner now! 🎉

And thanks for taking care of not introducing breaking changes. I agree it makes imports redundant but for libraries like this one it's more important not to brake downstream usage rather than having a perfectly clean library internally.