Listable V3 Stores (#1634)

* basic support for v2 and v3 groups

* second rev on group apis

- removed abcs for groups/arrays
- improved return types in group.py
- warn (temporarily) when an implicit group is found
- add attributes.py with Attributes class

add test file

wip

* progress on store interface (memory and local stores only)

fixes after rebas
e

make all tests pass

Author: jhamman

.gitignore

@@ -78,5 +78,6 @@ src/zarr/_version.py
 #doesnotexist
 #test_sync*
 data/*
+src/fixture/
 
 .DS_Store

src/zarr/v3/__init__.py

@@ -6,14 +6,9 @@
 from zarr.v3.array import Array  # noqa: F401
 from zarr.v3.array_v2 import ArrayV2  # noqa: F401
 from zarr.v3.group import Group  # noqa: F401
-from zarr.v3.group_v2 import GroupV2  # noqa: F401
 from zarr.v3.metadata import RuntimeConfiguration, runtime_configuration  # noqa: F401
 from zarr.v3.store import (  # noqa: F401
-    LocalStore,
-    RemoteStore,
-    Store,
     StoreLike,
-    StorePath,
     make_store_path,
 )
 from zarr.v3.sync import sync as _sync
@@ -22,18 +17,18 @@
 async def open_auto_async(
     store: StoreLike,
     runtime_configuration_: RuntimeConfiguration = RuntimeConfiguration(),
-) -> Union[Array, ArrayV2, Group, GroupV2]:
+) -> Union[Array, ArrayV2, Group]:
     store_path = make_store_path(store)
     try:
-        return await Group.open_or_array(store_path, runtime_configuration=runtime_configuration_)
+        return await Array.open(store_path, runtime_configuration=runtime_configuration_)
     except KeyError:
-        return await GroupV2.open_or_array(store_path, runtime_configuration_)
+        return await Group.open(store_path, runtime_configuration=runtime_configuration_)
 
 
 def open_auto(
     store: StoreLike,
     runtime_configuration_: RuntimeConfiguration = RuntimeConfiguration(),
-) -> Union[Array, ArrayV2, Group, GroupV2]:
+) -> Union[Array, ArrayV2, Group]:
     return _sync(
         open_auto_async(store, runtime_configuration_),
         runtime_configuration_.asyncio_loop,