Description
Describe the issue linked to the documentation
It looks like you've completely changed the exceptions under zarr.errors in the transition from v2 to v3. Our v2 code catches zarr.errors.PathNotFoundError to determine if a zarr store exists, but v3 appears to be using python's FileNotFound exception now. This makes a lot of sense, but it is a change that anyone who catches v2 exceptions will need to know about.
Here's the errors in v2:
>>> import inspect
>>> import zarr
>>> for name,cls in inspect.getmembers(zarr.errors,inspect.isclass):
... print(cls)
...
<class 'zarr.errors.ArrayIndexError'>
<class 'zarr.errors.ArrayNotFoundError'>
<class 'zarr.errors.BadCompressorError'>
<class 'zarr.errors.BoundsCheckError'>
<class 'zarr.errors.ContainsArrayError'>
<class 'zarr.errors.ContainsGroupError'>
<class 'zarr.errors.CopyError'>
<class 'zarr.errors.FSPathExistNotDir'>
<class 'zarr.errors.GroupNotFoundError'>
<class 'zarr.errors.MetadataError'>
<class 'zarr.errors.NegativeStepError'>
<class 'zarr.errors.PathNotFoundError'>
<class 'zarr.errors.ReadOnlyError'>
<class 'zarr.errors.VindexInvalidSelectionError'>
<class 'zarr.errors._BaseZarrError'>
<class 'zarr.errors._BaseZarrIndexError'>And here's v3:
>>> import inspect
>>> import zarr
>>> for name,cls in inspect.getmembers(zarr.errors,inspect.isclass):
... print(cls)
...
typing.Any
<class 'zarr.errors.BaseZarrError'>
<class 'zarr.errors.ContainsArrayAndGroupError'>
<class 'zarr.errors.ContainsArrayError'>
<class 'zarr.errors.ContainsGroupError'>
<class 'zarr.errors.MetadataValidationError'>
<class 'zarr.errors.NodeTypeValidationError'>Given that there are many fewer v3 exceptions, I'm guessing you decided to clean up and consolidate your exception classes.
Suggested fix for documentation
I think that in the 3.0 Migration Guide, the section "Getting ready for 3.0", number 2 should include something short about the zarr.errors library. Unless you have an easy to understand grand philosophy for how you made these changes, I'm happy to submit a pull request with some generic language.