adds deprecated compressor arg to Group.create_array

Author: normanrz

src/zarr/api/synchronous.py

@@ -18,7 +18,12 @@
 
     from zarr.abc.codec import Codec
     from zarr.api.asynchronous import ArrayLike, PathLike
-    from zarr.core.array import CompressorsLike, FiltersLike, SerializerLike, ShardsLike
+    from zarr.core.array import (
+        CompressorsLike,
+        FiltersLike,
+        SerializerLike,
+        ShardsLike,
+    )
     from zarr.core.array_spec import ArrayConfig, ArrayConfigLike
     from zarr.core.buffer import NDArrayLike
     from zarr.core.chunk_key_encodings import ChunkKeyEncoding, ChunkKeyEncodingLike

src/zarr/core/_info.py

@@ -6,6 +6,7 @@
 import numpy as np
 
 from zarr.abc.codec import Codec
+from zarr.core.common import ZarrFormat
 from zarr.core.metadata.v3 import DataType
 
 
@@ -20,7 +21,7 @@ class GroupInfo:
 
     _name: str
     _type: Literal["Group"] = "Group"
-    _zarr_format: Literal[2, 3]
+    _zarr_format: ZarrFormat
     _read_only: bool
     _store_type: str
     _count_members: int | None = None
@@ -76,7 +77,7 @@ class ArrayInfo:
     """
 
     _type: Literal["Array"] = "Array"
-    _zarr_format: Literal[2, 3]
+    _zarr_format: ZarrFormat
     _data_type: np.dtype[Any] | DataType
     _shape: tuple[int, ...]
     _chunk_shape: tuple[int, ...] | None = None

src/zarr/core/array.py

@@ -3636,8 +3636,10 @@ def _get_default_codecs(
     | Literal["auto"]
     | None
 )
+CompressorLike: TypeAlias = dict[str, JSON] | BytesBytesCodec | numcodecs.abc.Codec | None
 CompressorsLike: TypeAlias = (
-    Iterable[dict[str, JSON] | BytesBytesCodec]
+    Iterable[dict[str, JSON] | BytesBytesCodec | numcodecs.abc.Codec]
+    | dict[str, JSON]
     | BytesBytesCodec
     | numcodecs.abc.Codec
     | Literal["auto"]
@@ -4064,3 +4066,18 @@ def _parse_chunk_encoding_v3(
         out_array_bytes = _parse_array_bytes_codec(serializer)
 
     return out_array_array, out_array_bytes, out_bytes_bytes
+
+
+def _parse_deprecated_compressor(
+    compressor: CompressorLike | None, compressors: CompressorsLike
+) -> CompressorsLike | None:
+    if compressor:
+        if compressors != "auto":
+            raise ValueError("Cannot specify both `compressor` and `compressors`.")
+        warn(
+            "The `compressor` argument is deprecated. Use `compressors` instead.",
+            category=UserWarning,
+            stacklevel=2,
+        )
+        compressors = (compressor,)
+    return compressors

src/zarr/core/group.py

@@ -1,4 +1,4 @@
-from typing import Any, Literal
+from typing import Any
 
 import hypothesis.extra.numpy as npst
 import hypothesis.strategies as st
@@ -8,6 +8,7 @@
 
 import zarr
 from zarr.core.array import Array
+from zarr.core.common import ZarrFormat
 from zarr.core.sync import sync
 from zarr.storage import MemoryStore, StoreLike
 from zarr.storage.common import _dereference_path
@@ -69,7 +70,7 @@ def v2_dtypes() -> st.SearchStrategy[np.dtype]:
 # So we map a clear to reset the store.
 stores = st.builds(MemoryStore, st.just({})).map(lambda x: sync(x.clear()))
 compressors = st.sampled_from([None, "default"])
-zarr_formats: st.SearchStrategy[Literal[2, 3]] = st.sampled_from([2, 3])
+zarr_formats: st.SearchStrategy[ZarrFormat] = st.sampled_from([2, 3])
 array_shapes = npst.array_shapes(max_dims=4, min_side=0)
 
 
@@ -78,7 +79,7 @@ def numpy_arrays(
     draw: st.DrawFn,
     *,
     shapes: st.SearchStrategy[tuple[int, ...]] = array_shapes,
-    zarr_formats: st.SearchStrategy[Literal[2, 3]] = zarr_formats,
+    zarr_formats: st.SearchStrategy[ZarrFormat] = zarr_formats,
 ) -> Any:
     """
     Generate numpy arrays that can be saved in the provided Zarr format.

src/zarr/testing/strategies.py

@@ -466,7 +466,7 @@ def test_vlen_errors() -> None:
 
 
 @pytest.mark.parametrize("zarr_format", [2, 3])
-def test_update_attrs(zarr_format: Literal[2, 3]) -> None:
+def test_update_attrs(zarr_format: ZarrFormat) -> None:
     # regression test for https://github.com/zarr-developers/zarr-python/issues/2328
     store = MemoryStore()
     arr = zarr.create_array(
@@ -799,7 +799,7 @@ def test_array_create_metadata_order_v2(
 @pytest.mark.parametrize("store", ["memory"], indirect=True)
 def test_array_create_order(
     order_config: MemoryOrder | None,
-    zarr_format: Literal[2, 3],
+    zarr_format: ZarrFormat,
     store: MemoryStore,
 ) -> None:
     """

tests/test_array.py

@@ -1427,3 +1427,13 @@ def test_delitem_removes_children(store: Store, zarr_format: ZarrFormat) -> None
     del g1["0"]
     with pytest.raises(KeyError):
         g1["0/0"]
+
+
+@pytest.mark.parametrize("store", ["local", "memory"], indirect=["store"])
+def test_deprecated_compressor(store: Store) -> None:
+    g = zarr.group(store=store, zarr_format=2)
+    with pytest.warns(UserWarning, match="The `compressor` argument is deprecated.*"):
+        a = g.create_array(
+            "foo", shape=(100,), chunks=(10,), dtype="i4", compressor={"id": "blosc"}
+        )
+        assert a.metadata.compressor.codec_id == "blosc"