try workaround for Python 3.7 NORMAL_COLOR = 255, 0, 255 problem

src/extract_otp_secrets.py

@@ -86,16 +86,24 @@ Exception: {e}""")
     Point = Tuple[int, int]
 
     # CV2 camera capture constants
-    NORMAL_COLOR: Final[ColorBGR] = 255, 0, 255
-    SUCCESS_COLOR: Final[ColorBGR] = 0, 255, 0
-    FAILURE_COLOR: Final[ColorBGR] = 0, 0, 255
     FONT: Final[int] = cv2.FONT_HERSHEY_PLAIN
     FONT_SCALE: Final[int] = 1
     FONT_THICKNESS: Final[int] = 1
-    START_POS_TEXT: Final[Point] = 5, 20
-    FONT_DY: Final[Tuple[int, int]] = 0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5
     FONT_LINE_STYLE: Final[int] = cv2.LINE_AA
     RECT_THICKNESS: Final[int] = 5
+    if sys.version_info >= (3, 8):
+        START_POS_TEXT: Final[Point] = 5, 20
+        NORMAL_COLOR: Final[ColorBGR] = 255, 0, 255
+        SUCCESS_COLOR: Final[ColorBGR] = 0, 255, 0
+        FAILURE_COLOR: Final[ColorBGR] = 0, 0, 255
+        FONT_DY: Final[Tuple[int, int]] = 0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5
+    else:
+        # workaround for Python 3.7
+        START_POS_TEXT = 5, 20
+        NORMAL_COLOR = 255, 0, 255
+        SUCCESS_COLOR = 0, 255, 0
+        FAILURE_COLOR = 0, 0, 255
+        FONT_DY = 0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5
 
     qreader_available = True
 except ImportError: