Starting on Version 7.0 using the work done by others. Completely untested. I will be testing things, but I thought I'd get this base version up for others to give pull requests.

THIS IS ON THE MASTER BRANCH. The Master branch will be Python 3.0 from now on. While Python 2.7 support will not be deliberately broken, all efforts should now focus on Python 3.0 compatibility.

I can see a lot of work has been done. There's more to do. I've bumped the version number of everything I came across to the next major number for Python 3.0 compatibility indication.

Thanks everyone. I hope to update here at least once a week until we have a stable 7.0 release for calibre 5.0

DeDRM_plugin/kfxdedrm.py

@@ -6,6 +6,9 @@ from __future__ import print_function
 
 # Engine to remove drm from Kindle KFX ebooks
 
+#  2.0   - Added Python 3 compatibility for calibre 5.0
+
+
 import os
 import shutil
 import zipfile
@@ -13,7 +16,10 @@ import zipfile
 try:
     from cStringIO import StringIO
 except ImportError:
-    from StringIO import StringIO
+    try:
+        from StringIO import StringIO
+    except ImportError:
+        from io import StringIO
 
 try:
     from calibre_plugins.dedrm import ion
@@ -22,7 +28,7 @@ except ImportError:
 
 
 __license__ = 'GPL v3'
-__version__ = '1.0'
+__version__ = '2.0'
 
 
 class KFXZipBook: