clean up parents

src/zarr/core/array.py

@@ -3,6 +3,7 @@
 import json
 from asyncio import gather
 from dataclasses import dataclass, field, replace
+from logging import getLogger
 from typing import TYPE_CHECKING, Any, Literal, cast
 
 import numpy as np
@@ -80,6 +81,8 @@
 # Array and AsyncArray are defined in the base ``zarr`` namespace
 __all__ = ["create_codec_pipeline", "parse_array_metadata"]
 
+logger = getLogger(__name__)
+
 
 def parse_array_metadata(data: Any) -> ArrayV2Metadata | ArrayV3Metadata:
     if isinstance(data, ArrayV2Metadata | ArrayV3Metadata):
@@ -636,6 +639,8 @@ async def _save_metadata(self, metadata: ArrayMetadata, ensure_parents: bool = F
             # To enable zarr.create(store, path="a/b/c"), we need to create all the intermediate groups.
             parents = _build_parents(self)
 
+            logger.debug("Ensure parents: %s", parents)
+
             for parent in parents:
                 awaitables.extend(
                     [
@@ -2385,11 +2390,9 @@ def chunks_initialized(array: Array | AsyncArray) -> tuple[str, ...]:
 def _build_parents(node: AsyncArray | AsyncGroup) -> list[AsyncGroup]:
     from zarr.core.group import AsyncGroup, GroupMetadata
 
-    if "/" in node.store_path.path:
-        required_parts = node.store_path.path.split("/")[:-1]
-    else:
-        required_parts = []
+    required_parts = node.store_path.path.split("/")[:-1]
     parents = [
+        # the root group
         AsyncGroup(
             metadata=GroupMetadata(zarr_format=node.metadata.zarr_format),
             store_path=StorePath(store=node.store_path.store, path=""),

src/zarr/core/group.py

@@ -836,6 +836,9 @@ def __setitem__(self, key: str, value: Any) -> None:
         """__setitem__ is not supported in v3"""
         raise NotImplementedError
 
+    def __repr__(self) -> str:
+        return f"<Group {self.store_path}>"
+
     async def update_attributes_async(self, new_attributes: dict[str, Any]) -> Group:
         new_metadata = replace(self.metadata, attributes=new_attributes)
 

tests/v3/test_group.py

@@ -237,9 +237,7 @@ def test_group_create(store: Store, exists_ok: bool, zarr_format: ZarrFormat) ->
 
     if not exists_ok:
         with pytest.raises(ContainsGroupError):
-            group = Group.from_store(
-                store, attributes=attributes, exists_ok=exists_ok, zarr_format=zarr_format
-            )
+            _ = Group.from_store(store, exists_ok=exists_ok, zarr_format=zarr_format)
 
 
 def test_group_open(store: Store, zarr_format: ZarrFormat, exists_ok: bool) -> None: