chore: spec0 compat (python 3.14 compat, numpy 2 min, python 3.12 min)

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -61,7 +61,7 @@ body:
       value: |
         ```python
         # /// script
-        # requires-python = ">=3.11"
+        # requires-python = ">=3.12"
         # dependencies = [
         #   "zarr@git+https://github.com/zarr-developers/zarr-python.git@main",
         # ]

.github/workflows/gpu_test.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: gpu-runner
     strategy:
       matrix:
-        python-version: ['3.11']
+        python-version: ['3.12']
         numpy-version: ['2.2']
         dependency-set: ["minimal"]
 

.github/workflows/nightly_wheels.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/setup-python@v6
         name: Install Python
         with:
-          python-version: '3.13'
+          python-version: '3.14'
 
       - name: Install build dependencies
         run: |

.github/workflows/releases.yml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/setup-python@v6
         name: Install Python
         with:
-          python-version: '3.11'
+          python-version: '3.12'
 
       - name: Install PyBuild
         run: |

.github/workflows/test.yml

@@ -20,24 +20,24 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ['3.11', '3.12', '3.13']
-        numpy-version: ['1.26', '2.2']
+        python-version: ['3.12', '3.13', '3.14']
+        numpy-version: ['2.0', '2.2']
         dependency-set: ["minimal", "optional"]
         os: ["ubuntu-latest"]
         include:
-          - python-version: '3.11'
-            numpy-version: '1.26'
+          - python-version: '3.12'
+            numpy-version: '2.0'
             dependency-set: 'optional'
             os: 'macos-latest'
-          - python-version: '3.13'
+          - python-version: '3.14'
             numpy-version: '2.2'
             dependency-set: 'optional'
             os: 'macos-latest'
-          - python-version: '3.11'
-            numpy-version: '1.26'
+          - python-version: '3.12'
+            numpy-version: '2.0'
             dependency-set: 'optional'
             os: 'windows-latest'
-          - python-version: '3.13'
+          - python-version: '3.14'
             numpy-version: '2.2'
             dependency-set: 'optional'
             os: 'windows-latest'
@@ -78,12 +78,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.11', "3.13"]
+        python-version: ['3.12', "3.14"]
         dependency-set: ["upstream", "min_deps"]
         exclude:
-          - python-version: "3.13"
+          - python-version: "3.14"
             dependency-set: min_deps
-          - python-version: "3.11"
+          - python-version: "3.12"
             dependency-set: upstream
     steps:
     - uses: actions/checkout@v6

.pre-commit-config.yaml

@@ -6,7 +6,7 @@ ci:
 default_stages: [pre-commit, pre-push]
 
 default_language_version:
-  python: python3.11
+  python: python3.14
 
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
@@ -37,7 +37,7 @@ repos:
           - donfig
           - numcodecs
           - google-crc32c>=1.5
-          - numpy==2.1 # until https://github.com/numpy/numpy/issues/28034 is resolved
+          - numpy
           - typing_extensions
           - universal-pathlib
           - obstore>=0.5.1

changes/3546.misc.md

@@ -0,0 +1 @@
+Upgrade to spec0 compat (python 3.14 max, python 3.12 min).

docs/contributing.md

@@ -155,7 +155,7 @@ When submitting a pull request, coverage will also be collected across all suppo
 
 ### Documentation
 
-Docstrings for user-facing classes and functions should follow the [numpydoc](https://numpydoc.readthedocs.io/en/stable/format.html#docstring-standard) standard, including sections for Parameters and Examples. All examples should run and pass as doctests under Python 3.11.
+Docstrings for user-facing classes and functions should follow the [numpydoc](https://numpydoc.readthedocs.io/en/stable/format.html#docstring-standard) standard, including sections for Parameters and Examples. All examples should run and pass as doctests under Python 3.12.
 
 Zarr uses mkdocs for documentation, hosted on readthedocs.org. Documentation is written in the Markdown markup language (.md files) in the `docs` folder. The documentation consists both of prose and API documentation. All user-facing classes and functions are included in the API documentation, under the `docs/api` folder using the [mkdocstrings](https://mkdocstrings.github.io/) extension. Add any new public functions or classes to the relevant markdown file in `docs/api/*.md`. Any new features or important usage information should be included in the user-guide (`docs/user-guide`). Any changes should also be included as a new file in the `changes` directory.
 

docs/index.md

@@ -21,7 +21,7 @@ Zarr-Python is a Python library for reading and writing Zarr groups and arrays.
 
 ## Installation
 
-Zarr requires Python 3.11 or higher. You can install it via `pip`:
+Zarr requires Python 3.12 or higher. You can install it via `pip`:
 
 ```bash
 pip install zarr

docs/user-guide/installation.md

@@ -4,9 +4,9 @@
 
 Required dependencies include:
 
-- [Python](https://docs.python.org/3/) (3.11 or later)
+- [Python](https://docs.python.org/3/) (3.12 or later)
 - [packaging](https://packaging.pypa.io) (22.0 or later)
-- [numpy](https://numpy.org) (1.26 or later)
+- [numpy](https://numpy.org) (2.0 or later)
 - [numcodecs](https://numcodecs.readthedocs.io) (0.14 or later)
 - [google-crc32c](https://github.com/googleapis/python-crc32c) (1.5 or later)
 - [typing_extensions](https://typing-extensions.readthedocs.io) (4.9 or later)

examples/custom_dtype/custom_dtype.py

@@ -1,5 +1,5 @@
 # /// script
-# requires-python = ">=3.11"
+# requires-python = ">=3.12"
 # dependencies = [
 #   "zarr @ git+https://github.com/zarr-developers/zarr-python.git@main",
 #   "ml_dtypes==0.5.1",

pyproject.toml

@@ -29,11 +29,11 @@ maintainers = [
     { name = "Tom Augspurger", email = "tom.w.augspurger@gmail.com" },
     { name = "Deepak Cherian" }
 ]
-requires-python = ">=3.11"
+requires-python = ">=3.12"
 # If you add a new dependency here, please also add it to .pre-commit-config.yml
 dependencies = [
     'packaging>=22.0',
-    'numpy>=1.26',
+    'numpy>=2',
     'numcodecs>=0.14',
     'google-crc32c>=1.5',
     'typing_extensions>=4.12',
@@ -52,9 +52,9 @@ classifiers = [
     'Topic :: Software Development :: Libraries :: Python Modules',
     'Operating System :: Unix',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.11',
     'Programming Language :: Python :: 3.12',
     'Programming Language :: Python :: 3.13',
+    'Programming Language :: Python :: 3.14',
 ]
 license = "MIT"
 license-files = ["LICENSE.txt"]
@@ -162,8 +162,8 @@ COV_CORE_CONFIG = ".coveragerc"
 COV_CORE_DATAFILE = ".coverage.eager"
 
 [[tool.hatch.envs.test.matrix]]
-python = ["3.11", "3.12", "3.13"]
-numpy = ["1.26", "2.2"]
+python = ["3.12", "3.13", "3.14"]
+numpy = ["2.0", "2.2"]
 deps = ["minimal", "optional"]
 
 [tool.hatch.envs.test.overrides]
@@ -191,8 +191,8 @@ dependencies = [
 features = ["test", "gpu"]
 
 [[tool.hatch.envs.gputest.matrix]]
-python = ["3.11", "3.12", "3.13"]
-numpy = ["1.26", "2.2"]
+python = ["3.12", "3.13"]
+numpy = ["2.0", "2.2"]
 version = ["minimal"]
 
 [tool.hatch.envs.gputest.scripts]
@@ -205,7 +205,7 @@ list-env = "pip list"
 
 [tool.hatch.envs.upstream]
 template = 'test'
-python = "3.13"
+python = "3.14"
 dependencies = [
     'packaging @ git+https://github.com/pypa/packaging',
     'numpy',  # from scientific-python-nightly-wheels
@@ -230,15 +230,15 @@ description = """Test environment for minimum supported dependencies
 See Spec 0000 for details and drop schedule: https://scientific-python.org/specs/spec-0000/
 """
 template = "test"
-python = "3.11"
+python = "3.12"
 dependencies = [
     'zarr[remote]',
     'packaging==22.*',
-    'numpy==1.26.*',
+    'numpy==2.0.*',
     'numcodecs==0.14.*',  # 0.14 needed for zarr3 codecs
     'fsspec==2023.10.0',
     's3fs==2023.10.0',
-    'universal_pathlib==0.0.22',
+    'universal_pathlib==0.2.0',
     'typing_extensions==4.12.*',
     'donfig==0.8.*',
     'obstore==0.5.*',
@@ -247,6 +247,9 @@ dependencies = [
     'zarr[remote_tests]',
 ]
 
+[tool.hatch.envs.defaults]
+installer = "uv"
+
 [tool.hatch.envs.docs]
 features = ['docs', 'remote']
 
@@ -351,7 +354,7 @@ ignore = [
 "tests/**" = ["ANN001", "ANN201", "RUF029", "SIM117", "SIM300"]
 
 [tool.mypy]
-python_version = "3.11"
+python_version = "3.12"
 ignore_missing_imports = true
 namespace_packages = false
 

src/zarr/_compat.py

@@ -2,7 +2,7 @@
 from collections.abc import Callable
 from functools import wraps
 from inspect import Parameter, signature
-from typing import TYPE_CHECKING, Any, TypeVar
+from typing import TYPE_CHECKING, Any
 
 import numpy as np
 from packaging.version import Version
@@ -12,12 +12,10 @@
 if TYPE_CHECKING:
     from numpy.typing import NDArray
 
-T = TypeVar("T")
-
 # Based off https://github.com/scikit-learn/scikit-learn/blob/e87b32a81c70abed8f2e97483758eb64df8255e9/sklearn/utils/validation.py#L63
 
 
-def _deprecate_positional_args(
+def _deprecate_positional_args[T](
     func: Callable[..., T] | None = None, *, version: str = "3.1.0"
 ) -> Callable[..., T]:
     """Decorator for methods that issues warnings for positional arguments.

src/zarr/abc/codec.py

@@ -2,7 +2,7 @@
 
 from abc import abstractmethod
 from collections.abc import Mapping
-from typing import TYPE_CHECKING, Generic, TypeGuard, TypeVar
+from typing import TYPE_CHECKING, TypeGuard
 
 from typing_extensions import ReadOnly, TypedDict
 
@@ -34,13 +34,11 @@
     "CodecPipeline",
 ]
 
-CodecInput = TypeVar("CodecInput", bound=NDBuffer | Buffer)
-CodecOutput = TypeVar("CodecOutput", bound=NDBuffer | Buffer)
+type CodecInput = NDBuffer | Buffer
+type CodecOutput = NDBuffer | Buffer
 
-TName = TypeVar("TName", bound=str, covariant=True)
 
-
-class CodecJSON_V2(TypedDict, Generic[TName]):
+class CodecJSON_V2[TName: str](TypedDict):
     """The JSON representation of a codec for Zarr V2"""
 
     id: ReadOnly[TName]
@@ -59,7 +57,7 @@ def _check_codecjson_v2(data: object) -> TypeGuard[CodecJSON_V2[str]]:
 """The widest type of JSON-like input that could specify a codec."""
 
 
-class BaseCodec(Metadata, Generic[CodecInput, CodecOutput]):
+class BaseCodec[CI: CodecInput, CO: CodecOutput](Metadata):
     """Generic base class for codecs.
 
     Codecs can be registered via zarr.codecs.registry.
@@ -137,13 +135,13 @@ def validate(
             The array chunk grid
         """
 
-    async def _decode_single(self, chunk_data: CodecOutput, chunk_spec: ArraySpec) -> CodecInput:
+    async def _decode_single(self, chunk_data: CO, chunk_spec: ArraySpec) -> CI:
         raise NotImplementedError  # pragma: no cover
 
     async def decode(
         self,
-        chunks_and_specs: Iterable[tuple[CodecOutput | None, ArraySpec]],
-    ) -> Iterable[CodecInput | None]:
+        chunks_and_specs: Iterable[tuple[CO | None, ArraySpec]],
+    ) -> Iterable[CI | None]:
         """Decodes a batch of chunks.
         Chunks can be None in which case they are ignored by the codec.
 
@@ -154,25 +152,23 @@ async def decode(
 
         Returns
         -------
-        Iterable[CodecInput | None]
+        Iterable[CI | None]
         """
         return await _batching_helper(self._decode_single, chunks_and_specs)
 
-    async def _encode_single(
-        self, chunk_data: CodecInput, chunk_spec: ArraySpec
-    ) -> CodecOutput | None:
+    async def _encode_single(self, chunk_data: CI, chunk_spec: ArraySpec) -> CO | None:
         raise NotImplementedError  # pragma: no cover
 
     async def encode(
         self,
-        chunks_and_specs: Iterable[tuple[CodecInput | None, ArraySpec]],
-    ) -> Iterable[CodecOutput | None]:
+        chunks_and_specs: Iterable[tuple[CI | None, ArraySpec]],
+    ) -> Iterable[CO | None]:
         """Encodes a batch of chunks.
         Chunks can be None in which case they are ignored by the codec.
 
         Parameters
         ----------
-        chunks_and_specs : Iterable[tuple[CodecInput | None, ArraySpec]]
+        chunks_and_specs : Iterable[tuple[CI | None, ArraySpec]]
             Ordered set of to-be-encoded chunks with their accompanying chunk spec.
 
         Returns
@@ -460,21 +456,21 @@ async def write(
         ...
 
 
-async def _batching_helper(
-    func: Callable[[CodecInput, ArraySpec], Awaitable[CodecOutput | None]],
-    batch_info: Iterable[tuple[CodecInput | None, ArraySpec]],
-) -> list[CodecOutput | None]:
+async def _batching_helper[CI: CodecInput, CO: CodecOutput](
+    func: Callable[[CI, ArraySpec], Awaitable[CO | None]],
+    batch_info: Iterable[tuple[CI | None, ArraySpec]],
+) -> list[CO | None]:
     return await concurrent_map(
         list(batch_info),
         _noop_for_none(func),
         config.get("async.concurrency"),
     )
 
 
-def _noop_for_none(
-    func: Callable[[CodecInput, ArraySpec], Awaitable[CodecOutput | None]],
-) -> Callable[[CodecInput | None, ArraySpec], Awaitable[CodecOutput | None]]:
-    async def wrap(chunk: CodecInput | None, chunk_spec: ArraySpec) -> CodecOutput | None:
+def _noop_for_none[CI: CodecInput, CO: CodecOutput](
+    func: Callable[[CI, ArraySpec], Awaitable[CO | None]],
+) -> Callable[[CI | None, ArraySpec], Awaitable[CO | None]]:
+    async def wrap(chunk: CI | None, chunk_spec: ArraySpec) -> CO | None:
         if chunk is None:
             return None
         return await func(chunk, chunk_spec)

src/zarr/abc/numcodec.py

@@ -1,6 +1,4 @@
-from typing import Any, Self, TypeGuard
-
-from typing_extensions import Protocol
+from typing import Any, Protocol, Self, TypeGuard
 
 
 class Numcodec(Protocol):

src/zarr/abc/store.py

@@ -9,7 +9,7 @@
 if TYPE_CHECKING:
     from collections.abc import AsyncGenerator, AsyncIterator, Iterable
     from types import TracebackType
-    from typing import Any, Self, TypeAlias
+    from typing import Any, Self
 
     from zarr.core.buffer import Buffer, BufferPrototype
 
@@ -42,7 +42,7 @@ class SuffixByteRequest:
     """The number of bytes from the suffix to request."""
 
 
-ByteRequest: TypeAlias = RangeByteRequest | OffsetByteRequest | SuffixByteRequest
+type ByteRequest = RangeByteRequest | OffsetByteRequest | SuffixByteRequest
 
 
 class Store(ABC):