Only import from typing_extensions if needed

TypeAlias was included in the typing module in Python 3.10.
Self was included in the typing module in Python 3.11.

Author: ppentchev

src/libtmux/server.py

@@ -33,7 +33,12 @@
 )
 
 if t.TYPE_CHECKING:
-    from typing_extensions import TypeAlias
+    import sys
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
 
     DashLiteral: TypeAlias = t.Literal["-"]
 

src/libtmux/test.py

@@ -15,15 +15,20 @@
 logger = logging.getLogger(__name__)
 
 if t.TYPE_CHECKING:
+    import sys
     import types
     from collections.abc import Callable, Generator
 
-    from typing_extensions import Self
-
     from libtmux.server import Server
     from libtmux.session import Session
     from libtmux.window import Window
 
+    if sys.version_info >= (3, 11):
+        from typing import Self
+    else:
+        from typing_extensions import Self
+
+
 TEST_SESSION_PREFIX = "libtmux_"
 RETRY_TIMEOUT_SECONDS = int(os.getenv("RETRY_TIMEOUT_SECONDS", 8))
 RETRY_INTERVAL_SECONDS = float(os.getenv("RETRY_INTERVAL_SECONDS", 0.05))

tests/legacy_api/test_version.py

@@ -11,10 +11,15 @@
 from libtmux._compat import LooseVersion
 
 if t.TYPE_CHECKING:
+    import sys
     from collections.abc import Callable
 
     from _pytest.python_api import RaisesContext
-    from typing_extensions import TypeAlias
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
 
     VersionCompareOp: TypeAlias = Callable[
         [t.Any, t.Any],

tests/test_version.py

@@ -11,10 +11,15 @@
 from libtmux._compat import LooseVersion
 
 if t.TYPE_CHECKING:
+    import sys
     from collections.abc import Callable
 
     from _pytest.python_api import RaisesContext
-    from typing_extensions import TypeAlias
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
 
     VersionCompareOp: TypeAlias = Callable[
         [t.Any, t.Any],