added ruff code reivew

scripts/example_uart.py

@@ -46,7 +46,7 @@ import os
 import shlex
 import sys
 from pathlib import Path
-from typing import Optional, Union
+from typing import Union
 
 os.environ.setdefault("OPENCV_VIDEOIO_MSMF_ENABLE_HW_TRANSFORMS", "0")
 
@@ -60,13 +60,14 @@ except ImportError as exc:  # pragma: no cover
     ) from exc
 
 import cv2
+
 from orisys.capture import is_live_camera, list_cameras
 from orisys.finger import FingerRuntime
 
 Source = Union[int, str]
 
 
-def _parse_source(token: str) -> Optional[Source]:
+def _parse_source(token: str) -> Source | None:
     """Accept camera index int, numeric string, V4L path, or filesystem path."""
     text = str(token).strip().strip('"').strip("'")
     if not text:
@@ -116,9 +117,9 @@ class UartFingerController:
         self.show = show
         self.verbose = verbose
 
-        self.runtime: Optional[FingerRuntime] = None
-        self._connected_source: Optional[Source] = None
-        self._last_search_source: Optional[Source] = None
+        self.runtime: FingerRuntime | None = None
+        self._connected_source: Source | None = None
+        self._last_search_source: Source | None = None
         self._streaming = False
         self._should_quit = False
 
@@ -134,14 +135,18 @@ class UartFingerController:
         if self.runtime is not None:
             try:
                 self.runtime.close()
-            except Exception:  # noqa: BLE001
+            except Exception:  # noqa: BLE001, S110 - teardown must not raise
+                # Best-effort release: a close failure here has no recovery path in
+                # a shutdown request handler, and raising would skip the reset below.
                 pass
             self.runtime = None
             self._connected_source = None
         if self.show:
             try:
                 cv2.destroyAllWindows()
-            except Exception:  # noqa: BLE001
+            except Exception:  # noqa: BLE001, S110 - no GUI window to destroy
+                # Expected when no window was ever created (headless/--no-show run):
+                # this is a normal no-op, not a hidden failure.
                 pass
 
     def _resolve_connect_source(self, args: list[str]) -> Source:
@@ -220,7 +225,7 @@ class UartFingerController:
         except Exception:  # noqa: BLE001
             return False
 
-    def _poll_command_line(self, *, blocking: bool = True) -> Optional[str]:
+    def _poll_command_line(self, *, blocking: bool = True) -> str | None:
         """Read one command line if available; return None on timeout/empty."""
         if not blocking and self.ser.in_waiting <= 0:
             return None
@@ -447,7 +452,9 @@ def main(argv: list[str] | None = None) -> int:
         print("\nInterrupted.", flush=True)
         try:
             controller.reply("OK quit")
-        except Exception:  # noqa: BLE001
+        except Exception:  # noqa: BLE001, S110 - peer may already be gone
+            # We are already shutting down on Ctrl-C; failing to send the final
+            # acknowledgement (peer closed the port) must not mask the exit path.
             pass
     finally:
         controller.close_runtime()