simplify storepath creation

src/zarr/api/asynchronous.py

@@ -170,10 +170,7 @@ async def consolidate_metadata(
         The group, with the ``consolidated_metadata`` field set to include
         the metadata of each child node.
     """
-    store_path = await make_store_path(store)
-
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, path=path)
 
     group = await AsyncGroup.open(store_path, zarr_format=zarr_format, use_consolidated=False)
     group.store_path.store._check_writable()
@@ -291,10 +288,7 @@ async def open(
     """
     zarr_format = _handle_zarr_version_or_format(zarr_version=zarr_version, zarr_format=zarr_format)
 
-    store_path = await make_store_path(store, mode=mode, storage_options=storage_options)
-
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, mode=mode, path=path, storage_options=storage_options)
 
     if "shape" not in kwargs and mode in {"a", "w", "w-"}:
         try:
@@ -401,9 +395,7 @@ async def save_array(
     )
 
     mode = kwargs.pop("mode", None)
-    store_path = await make_store_path(store, mode=mode, storage_options=storage_options)
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
     new = await AsyncArray.create(
         store_path,
         zarr_format=zarr_format,
@@ -582,9 +574,7 @@ async def group(
 
     mode = None if isinstance(store, Store) else cast(AccessModeLiteral, "a")
 
-    store_path = await make_store_path(store, mode=mode, storage_options=storage_options)
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
 
     if chunk_store is not None:
         warnings.warn("chunk_store is not yet implemented", RuntimeWarning, stacklevel=2)
@@ -697,9 +687,7 @@ async def open_group(
     if chunk_store is not None:
         warnings.warn("chunk_store is not yet implemented", RuntimeWarning, stacklevel=2)
 
-    store_path = await make_store_path(store, mode=mode, storage_options=storage_options)
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, mode=mode, storage_options=storage_options, path=path)
 
     if attributes is None:
         attributes = {}
@@ -883,9 +871,7 @@ async def create(
         if not isinstance(store, Store | StorePath):
             mode = "a"
 
-    store_path = await make_store_path(store, mode=mode, storage_options=storage_options)
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
 
     return await AsyncArray.create(
         store_path,
@@ -925,6 +911,7 @@ async def empty(
     retrieve data from an empty Zarr array, any values may be returned,
     and these are not guaranteed to be stable from one access to the next.
     """
+
     return await create(shape=shape, fill_value=None, **kwargs)
 
 
@@ -1044,7 +1031,7 @@ async def open_array(
     store: StoreLike | None = None,
     zarr_version: ZarrFormat | None = None,  # deprecated
     zarr_format: ZarrFormat | None = None,
-    path: PathLike | None = None,
+    path: PathLike = "",
     storage_options: dict[str, Any] | None = None,
     **kwargs: Any,  # TODO: type kwargs as valid args to save
 ) -> AsyncArray[ArrayV2Metadata] | AsyncArray[ArrayV3Metadata]:
@@ -1071,9 +1058,7 @@ async def open_array(
     """
 
     mode = kwargs.pop("mode", None)
-    store_path = await make_store_path(store, mode=mode)
-    if path is not None:
-        store_path = store_path / path
+    store_path = await make_store_path(store, path=path, mode=mode)
 
     zarr_format = _handle_zarr_version_or_format(zarr_version=zarr_version, zarr_format=zarr_format)
 

src/zarr/storage/_utils.py

@@ -1,23 +1,30 @@
 from __future__ import annotations
 
+from pathlib import Path
 from typing import TYPE_CHECKING
 
+from upath import UPath
+
 if TYPE_CHECKING:
     from zarr.core.buffer import Buffer
 
 
-def normalize_path(path: str | bytes | object) -> str:
+def normalize_path(path: str | bytes | Path | UPath | None) -> str:
     # handle bytes
-    if isinstance(path, bytes):
+    if path is None:
+        result = ""
+    elif isinstance(path, bytes):
         result = str(path, "ascii")
-
     # ensure str
-    elif not isinstance(path, str):
+    elif isinstance(path, Path | UPath):
         result = str(path)
 
-    else:
+    elif isinstance(path, str):
         result = path
 
+    else:
+        raise TypeError(f'Object {path} has an invalid type for "path": {type(path).__name__}')
+
     # convert backslash to forward slash
     result = result.replace("\\", "/")
 
@@ -44,7 +51,7 @@ def normalize_path(path: str | bytes | object) -> str:
     segments = result.split("/")
     if any(s in {".", ".."} for s in segments):
         raise ValueError(
-            f"The path {path} is invalid because its string representation contains '.' or '..' segments."
+            f"The path {path!r} is invalid because its string representation contains '.' or '..' segments."
         )
 
     return result

src/zarr/storage/common.py

@@ -8,6 +8,7 @@
 from zarr.core.buffer import Buffer, default_buffer_prototype
 from zarr.core.common import ZARR_JSON, ZARRAY_JSON, ZGROUP_JSON, ZarrFormat
 from zarr.errors import ContainsArrayAndGroupError, ContainsArrayError, ContainsGroupError
+from zarr.storage._utils import normalize_path
 from zarr.storage.local import LocalStore
 from zarr.storage.memory import MemoryStore
 
@@ -41,9 +42,9 @@ class StorePath:
     store: Store
     path: str
 
-    def __init__(self, store: Store, path: str | None = None) -> None:
+    def __init__(self, store: Store, path: str = "") -> None:
         self.store = store
-        self.path = path or ""
+        self.path = path
 
     async def get(
         self,
@@ -159,6 +160,7 @@ def __eq__(self, other: object) -> bool:
 async def make_store_path(
     store_like: StoreLike | None,
     *,
+    path: str | None = "",
     mode: AccessModeLiteral | None = None,
     storage_options: dict[str, Any] | None = None,
 ) -> StorePath:
@@ -189,6 +191,9 @@ async def make_store_path(
     ----------
     store_like : StoreLike | None
         The object to convert to a `StorePath` object.
+    path: str | None, optional
+        The path to use when creating the `StorePath` object.  If None, the
+        default path is the empty string.
     mode : AccessModeLiteral | None, optional
         The mode to use when creating the `StorePath` object.  If None, the
         default mode is 'r'.
@@ -209,37 +214,44 @@ async def make_store_path(
     from zarr.storage.remote import RemoteStore  # circular import
 
     used_storage_options = False
-
+    path_normalized = normalize_path(path)
     if isinstance(store_like, StorePath):
         if mode is not None and mode != store_like.store.mode.str:
             _store = store_like.store.with_mode(mode)
             await _store._ensure_open()
-            store_like = StorePath(_store)
-        result = store_like
+            store_like = StorePath(_store, path=store_like.path) / path_normalized
+        result = store_like / path_normalized
     elif isinstance(store_like, Store):
         if mode is not None and mode != store_like.mode.str:
             store_like = store_like.with_mode(mode)
         await store_like._ensure_open()
-        result = StorePath(store_like)
+        result = StorePath(store_like, path=path_normalized)
     elif store_like is None:
         # mode = "w" is an exception to the default mode = 'r'
-        result = StorePath(await MemoryStore.open(mode=mode or "w"))
+        result = StorePath(await MemoryStore.open(mode=mode or "w"), path=path_normalized)
     elif isinstance(store_like, Path):
-        result = StorePath(await LocalStore.open(root=store_like, mode=mode or "r"))
+        result = StorePath(
+            await LocalStore.open(root=store_like, mode=mode or "r"), path=path_normalized
+        )
     elif isinstance(store_like, str):
         storage_options = storage_options or {}
 
         if _is_fsspec_uri(store_like):
             used_storage_options = True
             result = StorePath(
-                RemoteStore.from_url(store_like, storage_options=storage_options, mode=mode or "r")
+                RemoteStore.from_url(store_like, storage_options=storage_options, mode=mode or "r"),
+                path=path_normalized,
             )
         else:
-            result = StorePath(await LocalStore.open(root=Path(store_like), mode=mode or "r"))
+            result = StorePath(
+                await LocalStore.open(root=Path(store_like), mode=mode or "r"), path=path_normalized
+            )
     elif isinstance(store_like, dict):
         # We deliberate only consider dict[str, Buffer] here, and not arbitrary mutable mappings.
         # By only allowing dictionaries, which are in-memory, we know that MemoryStore appropriate.
-        result = StorePath(await MemoryStore.open(store_dict=store_like, mode=mode or "r"))
+        result = StorePath(
+            await MemoryStore.open(store_dict=store_like, mode=mode or "r"), path=path_normalized
+        )
     else:
         msg = f"Unsupported type for store_like: '{type(store_like).__name__}'"  # type: ignore[unreachable]
         raise TypeError(msg)

tests/v3/test_group.py

@@ -587,6 +587,7 @@ def test_group_array_creation(
     assert empty_array.fill_value == 0
     assert empty_array.shape == shape
     assert empty_array.store_path.store == store
+    assert empty_array.store_path.path == "empty"
 
     empty_like_array = group.empty_like(name="empty_like", data=empty_array)
     assert isinstance(empty_like_array, Array)

tests/v3/test_store/test_core.py

@@ -2,7 +2,9 @@
 from pathlib import Path
 
 import pytest
+from upath import UPath
 
+from zarr.storage._utils import normalize_path
 from zarr.storage.common import StoreLike, StorePath, make_store_path
 from zarr.storage.local import LocalStore
 from zarr.storage.memory import MemoryStore
@@ -65,3 +67,29 @@ async def test_make_store_path_storage_options_raises(store_like: StoreLike) ->
 async def test_unsupported() -> None:
     with pytest.raises(TypeError, match="Unsupported type for store_like: 'int'"):
         await make_store_path(1)  # type: ignore[arg-type]
+
+
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/foo/bar",
+        "//foo/bar",
+        "foo///bar",
+        "foo/bar///",
+        Path("foo/bar"),
+        b"foo/bar",
+        UPath("foo/bar"),
+    ],
+)
+def test_normalize_path_valid(path: str | bytes | Path | UPath) -> None:
+    assert normalize_path(path) == "foo/bar"
+
+
+def test_normalize_path_none():
+    assert normalize_path(None) == ""
+
+
+@pytest.mark.parametrize("path", [".", ".."])
+def test_normalize_path_invalid(path: str):
+    with pytest.raises(ValueError):
+        normalize_path(path)