fix: Fix type hint support for Python 3.9

.github/workflows/test-python.yml

@@ -44,7 +44,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: ["3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
     steps:
       - uses: actions/checkout@v4
 

pyproject.toml

@@ -6,7 +6,7 @@ license = "MIT"
 readme = "README.md"
 authors = [{ name = "Kyle Barron", email = "kyle@developmentseed.org" }]
 requires-python = ">=3.9"
-dependencies = []
+dependencies = ["typing-extensions; python_version < '3.12'"]
 keywords = []
 classifiers = [
     "Development Status :: 4 - Beta",

src/obspec/_attributes.py

@@ -1,17 +1,23 @@
 from __future__ import annotations
 
-from typing import Literal, TypeAlias
+import sys
+from typing import Literal, Union
 
-Attribute: TypeAlias = (
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+Attribute: TypeAlias = Union[
     Literal[
         "Content-Disposition",
         "Content-Encoding",
         "Content-Language",
         "Content-Type",
         "Cache-Control",
-    ]
-    | str
-)
+    ],
+    str,
+]
 """Additional object attribute types.
 
 - `"Content-Disposition"`: Specifies how the object should be handled by a browser.

src/obspec/_get.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Protocol, Self, TypedDict
+from typing import TYPE_CHECKING, Protocol, TypedDict
 
 if TYPE_CHECKING:
     import sys
@@ -10,6 +10,11 @@
     from ._attributes import Attributes
     from ._meta import ObjectMeta
 
+    if sys.version_info >= (3, 11):
+        from typing import Self
+    else:
+        from typing_extensions import Self
+
     if sys.version_info >= (3, 12):
         from collections.abc import Buffer
     else:

src/obspec/_list.py

@@ -1,19 +1,17 @@
 from __future__ import annotations
 
+import sys
 from collections.abc import Sequence
-from typing import (
-    Generic,
-    Literal,
-    Protocol,
-    Self,
-    TypedDict,
-    TypeVar,
-    overload,
-)
+from typing import Generic, Literal, Protocol, TypedDict, TypeVar, overload
 
 from ._meta import ObjectMeta
 from .arrow import ArrowArrayExportable, ArrowStreamExportable
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self
+
 ListChunkType_co = TypeVar(
     "ListChunkType_co",
     Sequence[ObjectMeta],

src/obspec/_put.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import IO, TYPE_CHECKING, Literal, Protocol, TypeAlias, TypedDict
+from typing import IO, TYPE_CHECKING, Literal, Protocol, TypedDict, Union
 
 if TYPE_CHECKING:
     import sys
@@ -9,6 +9,11 @@
 
     from ._attributes import Attributes
 
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
+
     if sys.version_info >= (3, 12):
         from collections.abc import Buffer
     else:
@@ -32,7 +37,7 @@ class UpdateVersion(TypedDict, total=False):
     """A version indicator for the newly created object."""
 
 
-PutMode: TypeAlias = Literal["create", "overwrite"] | UpdateVersion
+PutMode: TypeAlias = Union[Literal["create", "overwrite"], UpdateVersion]
 """Configure preconditions for the put operation
 
 There are three modes: