Self-review

distributed/protocol/compression.py

@@ -7,11 +7,10 @@
 
 import warnings
 import zlib
-from collections.abc import Iterable
+from collections.abc import Callable, Iterable
 from contextlib import suppress
 from functools import lru_cache, partial
 from random import randint
-from typing import Callable  # TODO import from collections.abc (requires Python >=3.9)
 from typing import TYPE_CHECKING, Any, Literal
 
 from packaging.version import parse as parse_version
@@ -32,8 +31,8 @@
     "remote-worker", "remote-client", "localhost", "spill"
 ]
 AnyBytes: TypeAlias = "bytes | bytearray | memoryview"
-Compress: TypeAlias = Callable[[AnyBytes], AnyBytes]
-Decompress: TypeAlias = Compress
+Compress: TypeAlias = "Callable[[AnyBytes], AnyBytes]"
+Decompress: TypeAlias = "Callable[[AnyBytes], AnyBytes]"
 
 compressions: dict[CompressionName, tuple[CompressionName, Compress, Decompress]] = {
     None: (None, identity, identity),
@@ -55,7 +54,7 @@
     try:
         snappy.compress(memoryview(b""))
     except TypeError:
-        raise ImportError("Need snappy >= 0.5.3")  # pragma: nocover
+        raise ImportError("Need snappy >= 0.5.3")
 
     compressions["snappy"] = ("snappy", snappy.compress, snappy.decompress)
     compressions["auto"] = compressions["snappy"]
@@ -104,9 +103,7 @@ def zstd_decompress(data):
 
 
 @lru_cache
-def get_compression_for_role(
-    role: CompressionRole,
-) -> CompressionName:
+def get_compression_for_role(role: CompressionRole) -> CompressionName:
     try:
         cfg = dask.config.get("distributed.comm.compression." + role)
     except (KeyError, TypeError):