remove try catch for type_extensions and replace with if sys.version_info

examples/top_lite_simulator.py

@@ -1,7 +1,7 @@
 """Lite simulation of the top linux command."""
-
 import datetime
 import random
+import sys
 import time
 from dataclasses import dataclass
 
@@ -10,10 +10,10 @@ from rich.console import Console
 from rich.live import Live
 from rich.table import Table
 
-try:
-    from typing_extensions import Literal
-except ImportError:
+if sys.version_info >= (3, 8):
     from typing import Literal
+else:
+    from typing_extensions import Literal
 
 
 @dataclass

rich/align.py

@@ -1,10 +1,11 @@
+import sys
 from itertools import chain
-from typing import Iterable, Optional, TYPE_CHECKING
+from typing import TYPE_CHECKING, Iterable, Optional
 
-try:
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
     from typing_extensions import Literal
-except ImportError:  # pragma: no cover
-    from typing import Literal  # type: ignore
 
 from .constrain import Constrain
 from .jupyter import JupyterMixin
@@ -12,9 +13,8 @@ from .measure import Measurement
 from .segment import Segment
 from .style import StyleType
 
-
 if TYPE_CHECKING:
-    from .console import Console, ConsoleOptions, RenderResult, RenderableType
+    from .console import Console, ConsoleOptions, RenderableType, RenderResult
 
 AlignMethod = Literal["left", "center", "right"]
 VerticalAlignMethod = Literal["top", "middle", "bottom"]

rich/box.py

@@ -1,9 +1,10 @@
+import sys
 from typing import TYPE_CHECKING, Iterable, List
 
-try:
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
     from typing_extensions import Literal
-except ImportError:  # pragma: no cover
-    from typing import Literal  # type: ignore
 
 
 from ._loop import loop_last

rich/live_render.py

@@ -1,10 +1,10 @@
-from threading import RLock
+import sys
 from typing import Optional, Tuple
 
-try:
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
     from typing_extensions import Literal
-except ImportError:  # pragma: no cover
-    from typing import Literal  # type: ignore
 
 
 from ._loop import loop_last