small cleanup

icechunk-python/pyproject.toml

@@ -64,6 +64,12 @@ strict = true
 warn_unreachable = true
 enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
 
+[[tool.mypy.overrides]]
+ignore_missing_imports = true
+module = [
+  "toolz.*",
+]
+
 [tool.ruff]
 line-length = 90
 exclude = ["*.ipynb"]

icechunk-python/python/icechunk/xarray.py

@@ -1,28 +1,26 @@
 #!/usr/bin/env python3
+import importlib
 from collections.abc import Hashable, Mapping, MutableMapping
+from dataclasses import dataclass, field
 from typing import Any, Literal
 
-
 import numpy as np
 import zarr
 
 from icechunk import IcechunkStore
-from .dask import stateful_store_reduce
-
+from icechunk.distributed import extract_store, merge_stores
 from xarray import Dataset
-from xarray.backends.zarr import ZarrStore
 from xarray.backends.common import ArrayWriter
-from dataclasses import dataclass, field
-from icechunk.distributed import extract_store, merge_stores
+from xarray.backends.zarr import ZarrStore
+
+from icechunk.dask import stateful_store_reduce
 
 ZarrWriteModes = Literal["w", "w-", "a", "a-", "r+", "r"]
 
 # TODO: import-time check on Xarray version
 #
 try:
-    import dask
-
-    has_dask = True
+    has_dask = importlib.util.find_spec("dask") is not None
 except ImportError:
     has_dask = False
 
@@ -179,8 +177,8 @@ def write_metadata(
             ``append_dim`` at the same time. To create empty arrays to fill
             in with ``region``, use the `XarrayDatasetWriter` directly.
         """
-        from xarray.backends.zarr import _choose_default_mode
         from xarray.backends.api import _validate_dataset_names, dump_to_store
+        from xarray.backends.zarr import _choose_default_mode
 
         # validate Dataset keys, DataArray names
         _validate_dataset_names(self.dataset)

icechunk-python/tests/test_distributed_writers.py

@@ -77,8 +77,7 @@ async def test_distributed_writers():
     )
     _first_snap = store.commit("array created")
 
-    with dask.config.set(scheduler=client):
-        store_dask(store, sources=[dask_array], targets=[zarray])
+    store_dask(store, sources=[dask_array], targets=[zarray])
     commit_res = store.commit("distributed commit")
     assert commit_res