Merge main

Author: agriyakhetarpal

.github/workflows/gpu_test.yml

@@ -25,7 +25,7 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.11']
-        numpy-version: ['2.1']
+        numpy-version: ['2.2']
         dependency-set: ["minimal"]
 
     steps:

.github/workflows/hypothesis.yaml

@@ -26,7 +26,7 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.11']
-        numpy-version: ['2.1']
+        numpy-version: ['2.2']
         dependency-set: ["optional"]
 
     steps:

.github/workflows/test.yml

@@ -21,7 +21,7 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.11', '3.12', '3.13']
-        numpy-version: ['1.25', '2.1']
+        numpy-version: ['1.25', '2.2']
         dependency-set: ["minimal", "optional"]
         os: ["ubuntu-latest"]
         include:
@@ -30,15 +30,15 @@ jobs:
             dependency-set: 'optional'
             os: 'macos-latest'
           - python-version: '3.13'
-            numpy-version: '2.1'
+            numpy-version: '2.2'
             dependency-set: 'optional'
             os: 'macos-latest'
           - python-version: '3.11'
             numpy-version: '1.25'
             dependency-set: 'optional'
             os: 'windows-latest'
           - python-version: '3.13'
-            numpy-version: '2.1'
+            numpy-version: '2.2'
             dependency-set: 'optional'
             os: 'windows-latest'
     runs-on: ${{ matrix.os }}

changes/3066.feature.rst

@@ -0,0 +1 @@
+Added `~zarr.errors.GroupNotFoundError`, which is raised when attempting to open a group that does not exist.

changes/3100.bugfix.rst

@@ -0,0 +1,3 @@
+For Zarr format 2, allow fixed-length string arrays to be created without automatically inserting a
+``Vlen-UT8`` codec in the array of filters. Fixed-length string arrays do not need this codec. This
+change fixes a regression where fixed-length string arrays created with Zarr Python 3 could not be read with Zarr Python 2.18.

pyproject.toml

@@ -149,7 +149,7 @@ features = ["test"]
 
 [[tool.hatch.envs.test.matrix]]
 python = ["3.11", "3.12", "3.13"]
-numpy = ["1.25", "2.1"]
+numpy = ["1.25", "2.2"]
 deps = ["minimal", "optional"]
 
 [tool.hatch.envs.test.overrides]
@@ -185,7 +185,7 @@ features = ["test", "gpu"]
 
 [[tool.hatch.envs.gputest.matrix]]
 python = ["3.11", "3.12", "3.13"]
-numpy = ["1.25", "2.1"]
+numpy = ["1.25", "2.2"]
 version = ["minimal"]
 
 [tool.hatch.envs.gputest.scripts]

src/zarr/api/asynchronous.py

@@ -39,7 +39,7 @@
 )
 from zarr.core.metadata import ArrayMetadataDict, ArrayV2Metadata, ArrayV3Metadata
 from zarr.core.metadata.v2 import _default_compressor, _default_filters
-from zarr.errors import NodeTypeValidationError
+from zarr.errors import GroupNotFoundError, NodeTypeValidationError
 from zarr.storage._common import make_store_path
 
 if TYPE_CHECKING:
@@ -836,7 +836,7 @@ async def open_group(
             overwrite=overwrite,
             attributes=attributes,
         )
-    raise FileNotFoundError(f"Unable to find group: {store_path}")
+    raise GroupNotFoundError(store, store_path.path)
 
 
 async def create(

src/zarr/core/array.py

@@ -768,14 +768,6 @@ def _create_metadata_v2(
 
         dtype = parse_dtype(dtype, zarr_format=2)
 
-        # inject VLenUTF8 for str dtype if not already present
-        if np.issubdtype(dtype, np.str_):
-            filters = filters or []
-            from numcodecs.vlen import VLenUTF8
-
-            if not any(isinstance(x, VLenUTF8) or x["id"] == "vlen-utf8" for x in filters):
-                filters = list(filters) + [VLenUTF8()]
-
         return ArrayV2Metadata(
             shape=shape,
             dtype=np.dtype(dtype),

src/zarr/errors.py

@@ -21,6 +21,14 @@ def __init__(self, *args: Any) -> None:
         super().__init__(self._msg.format(*args))
 
 
+class GroupNotFoundError(BaseZarrError, FileNotFoundError):
+    """
+    Raised when a group isn't found at a certain path.
+    """
+
+    _msg = "No group found in store {!r} at path {!r}"
+
+
 class ContainsGroupError(BaseZarrError):
     """Raised when a group already exists at a certain path."""
 

tests/test_array.py

@@ -1246,7 +1246,7 @@ async def test_invalid_v3_arguments(
             zarr.create(store=store, dtype="uint8", shape=(10,), zarr_format=3, **kwargs)
 
     @staticmethod
-    @pytest.mark.parametrize("dtype", ["uint8", "float32", "str"])
+    @pytest.mark.parametrize("dtype", ["uint8", "float32", "str", "U10", "S10", ">M8[10s]"])
     @pytest.mark.parametrize(
         "compressors",
         [