Set up isort in CI

.github/workflows/build.yml

@@ -73,6 +73,7 @@ jobs:
       matrix:
         toxenv:
           - flake8
+          - isort
 
     steps:
       - name: Git clone

imgdiff.py

@@ -4,19 +4,25 @@
 
 Released under the MIT licence.
 """
-import os
-import sys
+
 import optparse
+import os
 import shutil
 import subprocess
+import sys
 import tempfile
 import time
 
-# There are two ways PIL is packaged
+# There are two ways PIL used to be packaged
 try:
-    from PIL import Image, ImageDraw, ImageChops, ImageFilter
+    from PIL import Image, ImageChops, ImageDraw, ImageFilter
 except ImportError:
-    import Image, ImageDraw, ImageChops, ImageFilter
+    # This is the old way, and probably nobody uses it anymore.  (PIL's dead
+    # anyway, Pillow supplanted it.)
+    import Image
+    import ImageChops
+    import ImageDraw
+    import ImageFilter
 
 
 __version__ = '1.7.2.dev0'

setup.py

@@ -1,5 +1,6 @@
 #!/usr/bin/python
-import os, re
+import os
+import re
 
 from setuptools import setup
 

tests.py

@@ -4,15 +4,16 @@
 import sys
 import tempfile
 import unittest
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from io import StringIO
 
 import mock
 
 import imgdiff
 
+try:
+    from cStringIO import StringIO
+except ImportError:
+    from io import StringIO
+
 
 @mock.patch('sys.stderr', StringIO())
 class TestMain(unittest.TestCase):

tox.ini

@@ -23,3 +23,8 @@ commands =
 deps = flake8
 skip_install = true
 commands = flake8 imgdiff.py setup.py tests.py
+
+[testenv:isort]
+deps = isort
+skip_install = true
+commands = isort {posargs: -c --diff imgdiff.py setup.py tests.py}