id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1466586967,I_kwDOAMm_X85XaldX,7328,Zarr store array dtype changes for empty object string,85085,closed,0,,,2,2022-11-28T15:05:14Z,2023-06-16T03:56:16Z,2023-06-16T03:56:16Z,CONTRIBUTOR,,,,"### What happened?
Saving a dataset with an empty object (string) variable to zarr changes the dtype to float64.
### What did you expect to happen?
The dtype should remain as `O`, just as it does for non-empty object variables.
### Minimal Complete Verifiable Example
```Python
import numpy as np
import xarray as xr
ds = xr.Dataset({""a"": np.array([], dtype=""O"")})
ds[""a""].dtype
# prints: dtype('O')
ds.to_zarr(""a.zarr"")
ds = xr.open_dataset(""a.zarr"")
ds[""a""].dtype
# prints: dtype('float64')
```
### MVCE confirmation
- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [X] Complete example — the example is self-contained, including all data and the text of any traceback.
- [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.
### Relevant log output
_No response_
### Anything else we need to know?
_No response_
### Environment
INSTALLED VERSIONS
------------------
commit: None
python: 3.8.13 (default, Mar 28 2022, 06:16:26)
[Clang 12.0.0 ]
python-bits: 64
OS: Darwin
OS-release: 21.6.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8
LOCALE: ('en_GB', 'UTF-8')
libhdf5: None
libnetcdf: None
xarray: 2022.11.0
pandas: 1.5.0
numpy: 1.23.4
scipy: 1.9.2
netCDF4: None
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: 2.13.3
cftime: None
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: 2022.10.0
distributed: 2022.10.0
matplotlib: 3.6.1
cartopy: None
seaborn: 0.12.0
numbagg: None
fsspec: 2022.8.2
cupy: None
pint: None
sparse: None
flox: None
numpy_groupies: None
setuptools: 63.4.1
pip: 22.2.2
conda: None
pytest: 7.1.3
IPython: 8.5.0
sphinx: 4.2.0
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/7328/reactions"", ""total_count"": 2, ""+1"": 2, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue
1429920838,I_kwDOAMm_X85VOtxG,7243,Some aggregate operations using the array API fail,85085,open,0,,,0,2022-10-31T14:15:00Z,2023-01-15T16:02:00Z,,CONTRIBUTOR,,,,"### What happened?
Here are some tests demonstrating the problem https://github.com/pydata/xarray/commit/9d6269de9fec4c66aeade2fdf9829c6e066a6eac:
```
FAILED xarray/tests/test_array_api.py::test_aggregation[max] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation[min] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation[mean] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation[prod] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation[std] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation[var] - assert False
FAILED xarray/tests/test_array_api.py::test_aggregation_skipna[std] - TypeError: std() got an unexpected keyword argument 'ddof'
FAILED xarray/tests/test_array_api.py::test_aggregation_skipna[var] - TypeError: var() got an unexpected keyword argument 'ddof'
```
### What did you expect to happen?
_No response_
### Minimal Complete Verifiable Example
_No response_
### MVCE confirmation
- [ ] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [ ] Complete example — the example is self-contained, including all data and the text of any traceback.
- [ ] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [ ] New issue — a search of GitHub Issues suggests this is not a duplicate.
### Relevant log output
_No response_
### Anything else we need to know?
_No response_
### Environment
INSTALLED VERSIONS
------------------
commit: 9d6269de9fec4c66aeade2fdf9829c6e066a6eac
python: 3.8.13 (default, Mar 28 2022, 06:16:26)
[Clang 12.0.0 ]
python-bits: 64
OS: Darwin
OS-release: 21.6.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8
LOCALE: ('en_GB', 'UTF-8')
libhdf5: None
libnetcdf: None
xarray: 2022.6.1.dev63+ge6791852a
pandas: 1.5.0
numpy: 1.23.3
scipy: None
netCDF4: None
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: None
cftime: None
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: None
cartopy: None
seaborn: None
numbagg: None
fsspec: None
cupy: None
pint: None
sparse: None
flox: None
numpy_groupies: None
setuptools: 63.4.1
pip: 22.1.2
conda: None
pytest: 7.1.3
IPython: None
sphinx: None
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/7243/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue
1165277802,I_kwDOAMm_X85FdLpq,6347,Can't set write_empty_chunks in Zarr encoding,85085,closed,0,,,0,2022-03-10T14:11:36Z,2022-03-17T04:52:10Z,2022-03-17T04:52:10Z,CONTRIBUTOR,,,,"### What happened?
Zarr 2.11.0 made [a change where chunks with data equal to the fill value are no longer written to disk by default](https://zarr.readthedocs.io/en/stable/release.html#release-2-11-0). I would like to override the default, but this isn't possible using xarray's `to_zarr`.
### What did you expect to happen?
_No response_
### Minimal Complete Verifiable Example
```Python
import numpy as np
import xarray as xr
ds = xr.Dataset({""x"": ((""d1""), np.full((2,), np.nan))})
ds.to_zarr(""/tmp/ds.zarr"", encoding={""x"": {""write_empty_chunks"":True}})
```
### Relevant log output
```Python
Traceback (most recent call last):
File """", line 1, in
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/core/dataset.py"", line 2036, in to_zarr
return to_zarr(
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/backends/api.py"", line 1431, in to_zarr
dump_to_store(dataset, zstore, writer, encoding=encoding)
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/backends/api.py"", line 1119, in dump_to_store
store.store(variables, attrs, check_encoding, writer, unlimited_dims=unlimited_dims)
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/backends/zarr.py"", line 534, in store
self.set_variables(
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/backends/zarr.py"", line 581, in set_variables
encoding = extract_zarr_variable_encoding(
File ""/Users/tom/miniconda/envs/sgkit-3.8/lib/python3.8/site-packages/xarray/backends/zarr.py"", line 220, in extract_zarr_variable_encoding
raise ValueError(
ValueError: unexpected encoding parameters for zarr backend: ['write_empty_chunks']
```
### Anything else we need to know?
_No response_
### Environment
INSTALLED VERSIONS
------------------
commit: None
python: 3.8.12 (default, Oct 12 2021, 06:23:56)
[Clang 10.0.0 ]
python-bits: 64
OS: Darwin
OS-release: 19.6.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8
LOCALE: ('en_GB', 'UTF-8')
libhdf5: None
libnetcdf: None
xarray: 2022.3.0
pandas: 1.3.5
numpy: 1.21.5
scipy: 1.7.3
netCDF4: None
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: 2.11.0
cftime: None
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: 2022.01.0
distributed: 2022.01.0
matplotlib: 3.5.1
cartopy: None
seaborn: 0.11.2
numbagg: None
fsspec: 2022.01.0
cupy: None
pint: None
sparse: None
setuptools: 58.0.4
pip: 21.2.4
conda: None
pytest: 6.2.5
IPython: 8.0.1
sphinx: 4.2.0","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/6347/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue