I want to preface this by saying that this would be a minor UX improvement. Not blocking at all!
Context
Zarr is extensible with custom codecs, e.g. imagecodecs. Naturally, this can lead to situations where the environment in which a Zarr archive was written is not the same as the environment in which a Zarr archive is read. This can lead to missing codecs when trying to load data from a Zarr archive.
Description
If you try to access a Zarr array that uses a codec which is not registered locally, a generic ValueError is thrown.
ValueError: codec not available: 'imagecodecs_jpeg2k'
In downstream libraries that use Zarr under the hood, this makes it harder to catch this specific error and to suggest an appropriate solution.
Instead, it would be great if a custom error is thrown that holds some additional information. For example
class InvalidCodecError(Exception):
"""Raised when an expected codec is not registered."""
def __init__(self, codec_name: str):
self.codec_name = codec_name
super().__init__(f"Codec not available: '{codec_name}'")This would enable something like:
try:
arr = root["array"]
except InvalidCodecError as error:
if error.codec_name == "imagecodecs_jpeg2k":
raise RuntimeError("This Zarr archive requires `imagecodecs`, to install it use ...") from error
I want to preface this by saying that this would be a minor UX improvement. Not blocking at all!
Context
Zarr is extensible with custom codecs, e.g.
imagecodecs. Naturally, this can lead to situations where the environment in which a Zarr archive was written is not the same as the environment in which a Zarr archive is read. This can lead to missing codecs when trying to load data from a Zarr archive.Description
If you try to access a Zarr array that uses a codec which is not registered locally, a generic
ValueErroris thrown.In downstream libraries that use Zarr under the hood, this makes it harder to catch this specific error and to suggest an appropriate solution.
Instead, it would be great if a custom error is thrown that holds some additional information. For example
This would enable something like: