Update TryExcept(msg='...')` (#9261)

utils/__init__.py

@@ -9,7 +9,7 @@ import threading
 
 class TryExcept(contextlib.ContextDecorator):
     # YOLOv5 TryExcept class. Usage: @TryExcept() decorator or 'with TryExcept():' context manager
-    def __init__(self, msg='default message here'):
+    def __init__(self, msg=''):
         self.msg = msg
 
     def __enter__(self):
@@ -17,7 +17,7 @@ class TryExcept(contextlib.ContextDecorator):
 
     def __exit__(self, exc_type, value, traceback):
         if value:
-            print(f'{self.msg}: {value}')
+            print(f'{self.msg}{value}')
         return True
 
 

utils/metrics.py

@@ -186,7 +186,7 @@ class ConfusionMatrix:
         # fn = self.matrix.sum(0) - tp  # false negatives (missed detections)
         return tp[:-1], fp[:-1]  # remove background class
 
-    @TryExcept('WARNING: ConfusionMatrix plot failure')
+    @TryExcept('WARNING: ConfusionMatrix plot failure: ')
     def plot(self, normalize=True, save_dir='', names=()):
         import seaborn as sn