Possible Regression: 'Float32' object has no attribute 'value' raised when using zarr>3.0.10. #3396
Description
Zarr version
main@94983362f06f9bb4be3f04562b179549e36a87c4
Numcodecs version
0.16.2
Python Version
3.12.9
Operating System
Mac
Installation
uv
Description
I was trying to test #3369 for a project using titiler-multidim together with @maxrjones earlier, and ran into this issue.
I wrote out a native zarr v3 dataset (I believe it was using v3.0.8) on the NASA veda hub and downloaded it locally for testing. When I am trying to read that in with the newest version or the main branch I get the following error:
Traceback (most recent call last):
File "/Users/juliusbusecke/Code/titiler-multidim/temp_dont_commit/mre_object_has_no_attr_value.py", line 19, in <module>
ds = xr.open_dataset(
^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/api.py", line 679, in open_dataset
backend_ds = backend.open_dataset(
^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/zarr.py", line 1581, in open_dataset
ds = store_entrypoint.open_dataset(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/store.py", line 44, in open_dataset
vars, attrs = filename_or_obj.load()
^^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/common.py", line 312, in load
(_decode_variable_name(k), v) for k, v in self.get_variables().items()
^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/zarr.py", line 858, in get_variables
return FrozenDict((k, self.open_store_variable(k)) for k in self.array_keys())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/core/utils.py", line 415, in FrozenDict
return Frozen(dict(*args, **kwargs))
^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/zarr.py", line 858, in <genexpr>
return FrozenDict((k, self.open_store_variable(k)) for k in self.array_keys())
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/juliusbusecke/.cache/uv/environments-v2/mre-object-has-no-attr-value-cd1317b944d0d9b9/lib/python3.12/site-packages/xarray/backends/zarr.py", line 852, in open_store_variable
attributes["_FillValue"], original_zarr_dtype.value
^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Float32' object has no attribute 'value'
If I downgrade to v3.0.10 the read works fine, so I am wondering if this is a regression. I am a bit confused because Max showed me the regression tests which should cover exactly this case.
I uploaded the dataset to a public bucket, so the script below should be fully repoducible and the dataset inspectable. Thankfull for any pointers.
Steps to reproduce
# /// script
# requires-python = ">=3.10"
# dependencies = [
# "fsspec==2024.12.0",
# "s3fs==2024.12.0",
# "xarray==2025.1.1",
# "zarr @ git+https://github.com/zarr-developers/zarr-python@94983362f06f9bb4be3f04562b179549e36a87c4"
# ]
# ///
# To reproduce failure use dependencies above. To fix, swap "zarr @ git+https://github.com/zarr-developers/zarr-python@94983362f06f9bb4be3f04562b179549e36a87c4" for "zarr==3.0.10"
import xarray as xr
import zarr
zarr.print_debug_info()
ds = xr.open_dataset(
"s3://s3://nasa-eodc-public/jbusecke/reproducers/nldas3_subsampled.zarr",
engine='zarr',
storage_options={
"anon": True
}
)
print(ds)Additional output
Required dependencies:
packaging: 25.0
numpy: 2.3.2
numcodecs: 0.16.2
typing_extensions: 4.14.1
donfig: 0.8.1.post1
Optional dependencies:
botocore: 1.39.11
fsspec: 2024.12.0
numcodecs: 0.16.2
s3fs: 2024.12.0