we do not typing_extensions in 3.9+3.10 as well (dependency on Self)

caldav/davclient.py

@@ -31,9 +31,12 @@
 
 if sys.version_info < (3, 9):
     from typing import Iterable, Mapping
-    from typing_extensions import Self
 else:
     from collections.abc import Iterable, Mapping
+
+if sys.version_info < (3, 11):
+    from typing_extensions import Self
+else:
     from typing import Self
 
 

caldav/elements/base.py

@@ -15,12 +15,13 @@
 
 if sys.version_info < (3, 9):
     from typing import Iterable
-    from typing_extensions import Self
-    from typing_extensions import TypeAlias
 else:
     from collections.abc import Iterable
+
+if sys.version_info < (3, 11):
+    from typing_extensions import Self
+else:
     from typing import Self
-    from typing import TypeAlias
 
 
 class BaseElement:

caldav/lib/url.py

@@ -14,7 +14,7 @@
 from caldav.lib.python_utilities import to_normal_str
 from caldav.lib.python_utilities import to_unicode
 
-if sys.version_info < (3, 9):
+if sys.version_info < (3, 11):
     from typing_extensions import Self
 else:
     from typing import Self

caldav/objects.py

@@ -65,7 +65,6 @@ class hierarchy into a separate file)
     from typing import Iterable
     from typing_extensions import DefaultDict
     from typing_extensions import Literal
-    from typing_extensions import Self
 else:
     from collections.abc import Callable
     from collections.abc import Container
@@ -74,6 +73,10 @@ class hierarchy into a separate file)
     from collections.abc import Sequence
     from collections import defaultdict as DefaultDict
     from typing import Literal
+
+if sys.version_info < (3, 11):
+    from typing_extensions import Self
+else:
     from typing import Self
 
 _CC = TypeVar("_CC", bound="CalendarObjectResource")

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=64", "setuptools-scm[toml]>=8.0"]
+requires = ["setuptools>=64", "setuptools-scm[toml]>=7.0"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -26,7 +26,7 @@ dependencies = [
     "requests",
     "icalendar",
     "recurring-ical-events>=2.0.0",
-    "typing_extensions;python_version<'3.9'",
+    "typing_extensions;python_version<'3.11'",
 ]
 dynamic = ["version"]
 
@@ -44,7 +44,7 @@ test = [
 ]
 
 [tool.setuptools_scm]
-version_file = "caldav/_version.py"
+write_to = "caldav/_version.py"
 
 [tool.setuptools]
 py-modules = ["caldav"]