Fix python 2 compatibility

Author: vstoykov

imagekit/lib.py

@@ -1,4 +1,5 @@
 # flake8: noqa
+import sys
 
 # Required PIL classes may or may not be available from the root namespace
 # depending on the installation method used.
@@ -39,15 +40,18 @@ def emit(self, record):
 # This function will replace `unicode` used in the code
 # If Django version is under 1.5 then use `force_unicde`
 # It is used for compatibility between Python 2 and Python 3
-try:
-    from django.utils.encoding import (force_str as force_text,
-                                       force_bytes,
-                                       smart_str as smart_text)
-except ImportError:
-    # Django < 1.5
-    from django.utils.encoding import (force_unicode as force_text,
-                                       smart_str as force_bytes,
-                                       smart_unicode as smart_text)
+if sys.version_info >= (3, 0):
+    from django.utils.encoding import (force_bytes,
+                                      force_str as force_text,
+                                      smart_str as smart_text)
+else:
+    try:
+        from django.utils.encoding import force_text, force_bytes, smart_text
+    except ImportError:
+        # Django < 1.5
+        from django.utils.encoding import (force_unicode as force_text,
+                                        smart_str as force_bytes,
+                                        smart_unicode as smart_text)
 
 __all__ = ['Image', 'ImageColor', 'ImageChops', 'ImageEnhance', 'ImageFile',
            'ImageFilter', 'ImageDraw', 'ImageStat', 'StringIO', 'NullHandler',

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py27-django111
+    py27-django{111,18}
     py{36,37,38,39,310}-django{22,31,32},
     py310-djangomain,
     coverage-report
@@ -17,6 +17,7 @@ python =
 [testenv]
 deps =
     -r test-requirements.txt
+    django18: django~=1.8.0
     django111: django~=1.11.0
     django22: django~=2.2.0
     django31: django~=3.1.0