use typing_extensions only in <py3.9

caldav/davclient.py

@@ -9,7 +9,6 @@
 from urllib.parse import unquote
 
 import requests
-import typing_extensions
 from caldav.elements import dav
 from caldav.lib import error
 from caldav.lib.python_utilities import to_normal_str
@@ -32,8 +31,10 @@
 
 if sys.version_info < (3, 9):
     from typing import Iterable, Mapping
+    from typing_extensions import Self
 else:
     from collections.abc import Iterable, Mapping
+    from typing import Self
 
 
 class DAVResponse:
@@ -434,7 +435,7 @@ def __init__(
 
         self._principal = None
 
-    def __enter__(self) -> typing_extensions.Self:
+    def __enter__(self) -> Self:
         return self
 
     def __exit__(

caldav/elements/base.py

@@ -11,13 +11,16 @@
 from caldav.lib.python_utilities import to_unicode
 from lxml import etree
 from lxml.etree import _Element
-from typing_extensions import Self
-from typing_extensions import TypeAlias
+
 
 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
+    from typing import Self
+    from typing import TypeAlias
 
 
 class BaseElement:

caldav/lib/url.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 # -*- encoding: utf-8 -*-
+import sys
 import typing
 import urllib.parse
 from typing import Union
@@ -12,7 +13,11 @@
 
 from caldav.lib.python_utilities import to_normal_str
 from caldav.lib.python_utilities import to_unicode
-from typing_extensions import Self
+
+if sys.version_info < (3, 9):
+    from typing_extensions import Self
+else:
+    from typing import Self
 
 
 class URL:

caldav/objects.py

@@ -35,8 +35,6 @@ class hierarchy into a separate file)
 from dateutil.rrule import rrulestr
 from lxml import etree
 from lxml.etree import _Element
-from typing_extensions import Literal
-from typing_extensions import Self
 from vobject.base import VBase
 
 from .elements.base import BaseElement
@@ -66,13 +64,17 @@ class hierarchy into a separate file)
     from typing import Callable, Container, Iterator, Sequence
     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
     from collections.abc import Iterable
     from collections.abc import Iterator
     from collections.abc import Sequence
     from collections import defaultdict as DefaultDict
+    from typing import Literal
+    from typing import Self
 
 _CC = TypeVar("_CC", bound="CalendarObjectResource")
 log = logging.getLogger("caldav")