Fix pylint: do not use bare 'except' (#5025)

* Fix E722, do not use bare 'except'

* Remove used codes

* Add FileNotFoundError in LoadImagesAndLabels

* Remove AssertionError

* Ignore LoadImagesAndLabels

* Ignore downloads.py

* Ignore torch_utils.py

* Ignore train.py

* Ignore datasets.py

* Enable utils/download.py

* Fixing exception in thop

* Remove unused code

* Fixing exception in LoadImagesAndLabels

* Fixing exception in exif_size

* Fixing exception in parse_model

* Ignore exceptions in requests

* Revert the exception as suggested

* Revert the exception as suggested

utils/general.py

@@ -152,7 +152,7 @@ def is_colab():
     try:
         import google.colab
         return True
-    except Exception as e:
+    except ImportError:
         return False
 
 
@@ -160,6 +160,7 @@ def is_pip():
     # Is file in a pip package?
     return 'site-packages' in Path(__file__).resolve().parts
 
+
 def is_ascii(s=''):
     # Is string composed of all ASCII (no UTF) characters? (note str().isascii() introduced in python 3.7)
     s = str(s)  # convert list, tuple, None, etc. to str
@@ -741,11 +742,11 @@ def print_mutation(results, hyp, save_dir, bucket):
         data = pd.read_csv(evolve_csv)
         data = data.rename(columns=lambda x: x.strip())  # strip keys
         i = np.argmax(fitness(data.values[:, :7]))  #
-        f.write(f'# YOLOv5 Hyperparameter Evolution Results\n' +
+        f.write('# YOLOv5 Hyperparameter Evolution Results\n' +
                 f'# Best generation: {i}\n' +
                 f'# Last generation: {len(data)}\n' +
-                f'# ' + ', '.join(f'{x.strip():>20s}' for x in keys[:7]) + '\n' +
-                f'# ' + ', '.join(f'{x:>20.5g}' for x in data.values[i, :7]) + '\n\n')
+                '# ' + ', '.join(f'{x.strip():>20s}' for x in keys[:7]) + '\n' +
+                '# ' + ', '.join(f'{x:>20.5g}' for x in data.values[i, :7]) + '\n\n')
         yaml.safe_dump(hyp, f, sort_keys=False)
 
     if bucket: